replacing IACV- I have a few questions
03-16-2008, 11:33 PM
#1
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Join Date: Oct 2005
Posts: 40
replacing IACV- I have a few questions
car is a 2k max auto
I did a search and read mixed opinions on doing a idle relearn.Should I do it? have a link on the correct procedure? again I saw different relearn procedures with such odd things a keeping the wheel straight
I have no volt meter just basic hand tools aswell should I take it to the stealership for them to do the relearn? If I should would driving the car 20 mins to the stealership be ok?
any tips? or things I should know before I do this or is it pretty straight forward? it seems very straight forward by the location of the IACV.
thanks
I did a search and read mixed opinions on doing a idle relearn.Should I do it? have a link on the correct procedure? again I saw different relearn procedures with such odd things a keeping the wheel straight
I have no volt meter just basic hand tools aswell should I take it to the stealership for them to do the relearn? If I should would driving the car 20 mins to the stealership be ok?
any tips? or things I should know before I do this or is it pretty straight forward? it seems very straight forward by the location of the IACV.
thanks
03-17-2008, 09:43 AM
#3
its tricky to get the relearn done properly, if even one parameter is off, it will not work. I was able to do the relearn procedure on my friends 2000 se but it took me a few tries for it to work.
Doing it yourself - free
stealership - $95 here in springfield, MA
Doing it yourself - free
stealership - $95 here in springfield, MA
03-17-2008, 10:22 AM
#4
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Can you post a link of the way you did it?
03-17-2008, 10:39 AM
#5
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Location: Vancouver, BC
Posts: 933
PRE-CONDITIONING
Before performing “Idle Air Volume Learning”, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
I Battery voltage: More than 12.9V (At idle)
I Engine coolant temperature: 70 - 99°C (158 - 210°F)
I PNP switch: ON
I Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
I Cooling fan motor: Not operating
I Steering wheel: Neutral (Straight-ahead position)
I Vehicle speed: Stopped
I Transmission: Warmed-up
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
Then accomplish this: Without CONSULT-II
1. Turn ignition switch “ON” and wait at least 1 second.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PRE-CONDITIONING”
(previously mentioned) are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Disconnect throttle position sensor harness connector AT THE TB (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed M/T: 625±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing M/T: 15°±5° BTDC
A/T: 15°±5° BTDC (in “P” or “N” position)
Before performing “Idle Air Volume Learning”, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
I Battery voltage: More than 12.9V (At idle)
I Engine coolant temperature: 70 - 99°C (158 - 210°F)
I PNP switch: ON
I Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
I Cooling fan motor: Not operating
I Steering wheel: Neutral (Straight-ahead position)
I Vehicle speed: Stopped
I Transmission: Warmed-up
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
Then accomplish this: Without CONSULT-II
1. Turn ignition switch “ON” and wait at least 1 second.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PRE-CONDITIONING”
(previously mentioned) are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Disconnect throttle position sensor harness connector AT THE TB (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed M/T: 625±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing M/T: 15°±5° BTDC
A/T: 15°±5° BTDC (in “P” or “N” position)
Last edited by P. Samson; 03-17-2008 at 10:42 AM.
03-18-2008, 09:28 PM
#6
Junior Member
Join Date: Nov 2003
Posts: 43
PRE-CONDITIONING
Before performing “Idle Air Volume Learning”, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
I Battery voltage: More than 12.9V (At idle)
I Engine coolant temperature: 70 - 99°C (158 - 210°F)
I PNP switch: ON
I Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
I Cooling fan motor: Not operating
I Steering wheel: Neutral (Straight-ahead position)
I Vehicle speed: Stopped
I Transmission: Warmed-up
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
Then accomplish this: Without CONSULT-II
1. Turn ignition switch “ON” and wait at least 1 second.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PRE-CONDITIONING”
(previously mentioned) are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Disconnect throttle position sensor harness connector AT THE TB (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed M/T: 625±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing M/T: 15°±5° BTDC
A/T: 15°±5° BTDC (in “P” or “N” position)
Before performing “Idle Air Volume Learning”, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
I Battery voltage: More than 12.9V (At idle)
I Engine coolant temperature: 70 - 99°C (158 - 210°F)
I PNP switch: ON
I Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
I Cooling fan motor: Not operating
I Steering wheel: Neutral (Straight-ahead position)
I Vehicle speed: Stopped
I Transmission: Warmed-up
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
Then accomplish this: Without CONSULT-II
1. Turn ignition switch “ON” and wait at least 1 second.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PRE-CONDITIONING”
(previously mentioned) are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Disconnect throttle position sensor harness connector AT THE TB (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed M/T: 625±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing M/T: 15°±5° BTDC
A/T: 15°±5° BTDC (in “P” or “N” position)
I have read a lot about these issues with the 5th gen.
I have an Infiniti I30 2001.
one night the ECM burnt and next morning it did start but wouldn't turn on unless I pressed on gas while I was starting the car (it was fine when the car was warm). Mechanic said the P0505 code is in the engine and we changed the Throttle body and the ECM, then a friend with Cons. II came and reset the ECM with the Keys.
The guy who programmed the ECM didnt know anything about idle air control programming, he said the computer will learn everything by it self.
at the point a second problem much more major:
The car idled at 1700rpm and when it was warmed up the rpm would go up and down like hiccups. and the engine was acting funny.
When the car is in drive it does not act as bad, it has some nock here and there but in idle it goes crazy.
Do I need to flash the ECM and relearn the idle air by a dealer? will that fix my issue?
or is it something more serious?
like Mass air Flow MAF?
Please advise ASAP...
03-18-2008, 11:12 PM
#7
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Join Date: May 2004
Location: Vancouver, BC
Posts: 933
When you say you've changed the TB, what got changed.......just the IACV? The TB is comprised of the TB body and throttle plate assy. and the IACV is attached to the TB along with the Throttle Position Sensor. If the TPS was disturbed then there is a critical TPS adjustment and procedures to be accomplished. Did the TPS get removed and reinstalled or replaced? Did you forget to connect something? The knock sound you mentioned, sounds like detonation. I had that once (along with a wild idle) when I forgot to hook up a vacuum hose. Check that all the hose connections are on and tight......air/vacuum leaks will cause problems. Check all the electrical connectors again. The haywire idle is probably connected to the repair, unlikely it's the MAF (assuming it's connected). ECM reflash is not applicable. If everything is correctly installed, the engine, after warming up, should have a reasonably stable idle at, or close to the specified RPM. Also........when you turn the Ign. switch from OFF to ON (wait), and then back to OFF, can you hear a kind of weird "buzzing" from the TB? You should hear that sound.......it's the sound of the IACV operating.
03-19-2008, 06:24 AM
#8
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Join Date: Nov 2003
Posts: 43
P0505 Wild Idle at 1800rpm etc
When you say you've changed the TB, what got changed.......just the IACV? The TB is comprised of the TB body and throttle plate assy. and the IACV is attached to the TB along with the Throttle Position Sensor. If the TPS was disturbed then there is a critical TPS adjustment and procedures to be accomplished. Did the TPS get removed and reinstalled or replaced? Did you forget to connect something? The knock sound you mentioned, sounds like detonation. I had that once (along with a wild idle) when I forgot to hook up a vacuum hose. Check that all the hose connections are on and tight......air/vacuum leaks will cause problems. Check all the electrical connectors again. The haywire idle is probably connected to the repair, unlikely it's the MAF (assuming it's connected). ECM reflash is not applicable. If everything is correctly installed, the engine, after warming up, should have a reasonably stable idle at, or close to the specified RPM. Also........when you turn the Ign. switch from OFF to ON (wait), and then back to OFF, can you hear a kind of weird "buzzing" from the TB? You should hear that sound.......it's the sound of the IACV operating.
I just called around and asked for the IACV and junk yards told me that it only comes with the TB. so I think I got the whole TB.
I had it checked with 2-3 mechanics and my last mechanic sprayed all over the car to look for a leak and he didn't notice anything.
The first mechanic connected a Diagnostic OBD2 and said that the problem might be with cylinder Head Gasket. I took it 2nd mechanic and he checked it and listened and sprayed and said it is not a problem with Head Gasket. He believes the problem is with IACV due to the P0505 code. and since I have just changed it and with the history of ECM on fire he says it could be an electrical problem. like the harness or a wire that goes form IACV to ECM is burnt. He recommends I should find some one with the skil to follow the schematics of the car and check the parts and locate the problem.
He does not know any one with those skills nor do I. If anyone knows of anyone with that skill in NY I would appreciate it.
Symptoms that I see.
-The car turns on and starts fine.
-The car idles at around 1700-2000 rpm at "N"
-When the car is cold it idles smooth but once it gets warmed up in a min or so it goes wild. it is as if the computer is trying to learn or is trying different settings, the RPM rapidly goes up and down. The car sounds like a child is playing with the Gas pedal.
-Once I put it in Drive it smooths very much. (I believe this is due to the transmission accepting the energy from the engine) However here and there I feel knocks and the car does not drive smooth.
-When the car was on the second mechanic Disconnected the MAF and the cars wild idle rhythm got faster.(+ 5 error codes that was reset after)
air/vacuum leak is a reasonable diagnostic but I have no idea how to check it and where?
So you are saying it is for sure not MAF?
And for sure not a computer problem?
And it is not the problem of Learning Idell Air?
03-19-2008, 04:10 PM
#9
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Join Date: May 2004
Location: Vancouver, BC
Posts: 933
This issue always seems to be a can of worms. Yes, I guess that it could be the ECM as it's a used part (the same thing goes for the IACV obviously), but the ECM at least has detected a problem and set the P0505 code. But, if there are any air or vacuum leaks the ECM/IACV may not be able to control the idle. And everything else has to be assembled and adjusted correctly as well. Is there some slack in the throttle and cruise control cables when the throttle is "closed"? Do you have the start throttle stop vacuum actuator on your TB? If you do, make sure that it's operating (pulling the stop out of the way allowing the throttle (drum) to contact the fixed TB stop as soon as the engine starts? And you didn't answer my question about the TPS. Did it come with the used TB or was it transfered over from your original TB, or was it otherwise disturbed (screws loosened)? Are you able to hear the IACV as I described? Check fuse #58 which I'm pretty sure is the same for your I30. The fuse is in the fuse box beside the battery. Unless you've got a stable, in the ball park idle, the Idle Air Volume Learning is useless. You do really need someone who is very familiar with the car to look at it.
Last edited by P. Samson; 03-19-2008 at 04:13 PM.
03-19-2008, 04:42 PM
#10
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Join Date: Nov 2003
Posts: 43
This issue always seems to be a can of worms. Yes, I guess that it could be the ECM as it's a used part (the same thing goes for the IACV obviously), but the ECM at least has detected a problem and set the P0505 code. But, if there are any air or vacuum leaks the ECM/IACV may not be able to control the idle. And everything else has to be assembled and adjusted correctly as well. Is there some slack in the throttle and cruise control cables when the throttle is "closed"? Do you have the start throttle stop vacuum actuator on your TB? If you do, make sure that it's operating (pulling the stop out of the way allowing the throttle (drum) to contact the fixed TB stop as soon as the engine starts? And you didn't answer my question about the TPS. Did it come with the used TB or was it transfered over from your original TB, or was it otherwise disturbed (screws loosened)? Are you able to hear the IACV as I described? Check fuse #58 which I'm pretty sure is the same for your I30. The fuse is in the fuse box beside the battery. Unless you've got a stable, in the ball park idle, the Idle Air Volume Learning is useless. You do really need someone who is very familiar with the car to look at it.
they checked it out all the way for 90$ and came back with the same stupid problem...
I guess the TB that I got was bad and messed up the ECM.
so I am back to square one!
shopping for another ECM and TB. The dealers price was 1500$ for parts and 550$ for labor + tax.
Junk yard price is 250 ECM + 160 TB + 120 Dealer ECM programing + 60 installation of TB = 410$ vs. 2050$ at dealer
so one more time I will go the cheap way and cross my fingers...
This time I will change the TB and ECM at the same time w/ the Battery Disconnected then tow it to Dealer have them Reflash and do all the fancy work on it.
Do I need a new Throttel Gasket from dealer?
ONE final question though...
My original Computer Says the following number on it "3U" A56-Q80-ZA1
The new one I got was I guess C56-W57....
The part number I got from dealer is :
Engine Control Module With Traction Control 2371M5Y016RE
Throttle Body 161194Y900
Throttle Body Gasket 161752Y001
I checked online and the same part numbers are used in Maxima A/T w/ TCS. However when I call junk yards the part number they have on the ECM box are many different numbers so I am not sure if I can trust going with any other number on ECM as long as it is from a Maxima/I30 2000-2001 with Auto transmission and TCS or should I stick with hte exact same number?
Thank you for all your help
03-19-2008, 05:21 PM
#11
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Join Date: May 2004
Location: Vancouver, BC
Posts: 933
I think that you should check/verify with a dealer on the applicable ECM PNs for your car. I wouldn't trust online or wrecker supplied numbers. Getting an incorrect ECM would just be more misery for you. Because of the history of the IACVs on these cars, at least in theory, causing ECM failures, I think you'd be smart if you bought a new IACV and gasket and install it on your original TB. Any old, used IACV on a TB from the wreckers could be contaminated, corroded and/or seized up and you wouldn't know it until it might be too late, like you may have just found out. And the used TB and TPS might be suspect as well. You do at least know the history of your original TB. The TB to intake plenum gasket is a gasko-seal type I think, and should be reusable after visually checking it.
03-19-2008, 05:30 PM
#12
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I think that you should check/verify with a dealer on the applicable ECM PNs for your car. I wouldn't trust online or wrecker supplied numbers. Getting an incorrect ECM would just be more misery for you. Because of the history of the IACVs on these cars, at least in theory, causing ECM failures, I think you'd be smart if you bought a new IACV and gasket and install it on your original TB. Any old, used IACV on a TB from the wreckers could be contaminated, corroded and/or seized up and you wouldn't know it until it might be too late, like you may have just found out. And the used TB and TPS might be suspect as well. You do at least know the history of your original TB. The TB to intake plenum gasket is a gasko-seal type I think, and should be reusable after visually checking it.
If I find a wrecked Maxima/i30 2000-01 AT w/ TCS and take the ECM and TB/IACV from it after making sure that car turns on and has no problem with computer that will be great.
a new TB is 600$ at least.
I also found a service for repairing the ECM for 150$ which will be very helpful.
I will see what comes my way...
Wish there was a way to check the IACV/TB
03-19-2008, 06:23 PM
#13
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Location: Vancouver, BC
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The wreckers maybe only deal in the TB "assembly" because they don't want to do any disassembly or whatever, but previously there have been people on this forum who have replaced just the IACV (and the TPS) with new units. The FSM also shows these units as being replaceable. Unless things have changed and Nissan has got even more greedy?
03-19-2008, 06:32 PM
#14
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The wreckers maybe only deal in the TB "assembly" because they don't want to do any disassembly or whatever, but previously there have been people on this forum who have replaced just the IACV (and the TPS) with new units. The FSM also shows these units as being replaceable. Unless things have changed and Nissan has got even more greedy?
The TB ***. has these black plastic boxes on it ,the plugs, I dont see how they are separatable..?
anyway, what ever gets it done... they usually dont even separate the TB from the engine they just sell the whole thing.
I actually found a wrecked Maxima 2000 AT w/ TCS locally and the owner says it turns on fine. hopefully the ECM and TB from that should do the job.
03-19-2008, 07:09 PM
#15
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I don't think that ECM, if it's off a Fed. Spec. car, is the correct one. This should be your IACV here: http://www.courtesyparts.com/Merchan...ode=23781-A33B Does that not look familiar?
Last edited by P. Samson; 03-19-2008 at 07:12 PM.
03-19-2008, 07:22 PM
#16
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I don't think that ECM, if it's off a Fed. Spec. car, is the correct one. This should be your IACV here: http://www.courtesyparts.com/Merchan...ode=23781-A33B Does that not look familiar?
as for the IACV I see what you mean. Do you think a mechanic can change that easily?
I would rather get a new one like that. the price is not that bad. almost the same as the whole TB ***. used.
I have a feeling the ECM should be the same part number as Maxima of same class maybe the program they load on it is different and that can be fixed by reflash.
I have AllData program and when I look up the part number for ECM w/ TCS for Maxima and I30 2001 are the same part number as the part number I got from infiniti dealer. isnt that enough proof? don't you think?
03-19-2008, 07:50 PM
#17
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The 2000 Federal Specification cars (in other words.......not originally for sale in California, only originally sold in the other 49 states and Canada) have only 3 O2 sensors and no intake swirler, so the ECM I gotta believe is different. Do not go by the information on parts availability and the Part Numbers that you find on any of the online parts sales companies that you find on the internet no matter how "official" they look or claim to be. You have to go to or phone the parts department of a Nissan/Infiniti dealer to get the the real information and actual part numbers especially related to interchangeablity/effectivity etc.
03-19-2008, 07:57 PM
#18
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The 2000 Federal Specification cars (in other words.......not originally for sale in California, only originally sold in the other 49 states and Canada) have only 3 O2 sensors and no intake swirler, so the ECM I gotta believe is different. Do not go by the information on parts availability and the Part Numbers that you find on any of the online parts sales companies that you find on the internet no matter how "official" they look or claim to be. You have to go to or phone the parts department of a Nissan/Infiniti dealer to get the the real information and actual part numbers especially related to interchangeability/effectivity etc.
and I can return it after I believe.
as for the IACV that you sent me is that easy to change?
03-19-2008, 09:09 PM
#19
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The IACV (and gasket) is easy to change, but I believe the TB has to be removed. There are some basic checks for the IACV, couldn't the dealer have done that? Jeez.......you shouldn't have to actually order anything first. If you are still not 100% sure about the PNs, as I mentioned before, the dealer's parts people shouldn't mind checking PNs for you. They still should have access to a detailed parts catalogue with effectivity, interchangeability info and updated PNs etc. DO NOT expect to be able to "correct" an incorrect ECM by any "reflash". That's unlikely and is inherently risky anyway. Sorry if I sound redundant.
03-19-2008, 09:14 PM
#20
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The IACV (and gasket) is easy to change, but I believe the TB has to be removed. There are some basic checks for the IACV, couldn't the dealer have done that? Jeez.......you shouldn't have to actually order anything first. If you are still not 100% sure about the PNs, as I mentioned before, the dealer's parts people shouldn't mind checking PNs for you. They still should have access to a detailed parts catalogue with effectivity, interchangeability info and updated PNs etc. DO NOT expect to be able to "correct" an incorrect ECM by any "reflash". That's unlikely and is inherently risky anyway. Sorry if I sound redundant.
I am wondering why they said I have to change the whole TB if the IACV can be bought separately. makes me think they just dont care about peoples pocket.
I will calla round to dealers and will gather some info on the parts then.
Thank you very much.
03-20-2008, 08:30 AM
#22
Just buy the new IACV like P.Samson has advised. In fact, I have personally installed only the new stepper motor from the IACV assembly to fix an issue. It is the only thing that is really necessary, since the remainder of the assembly has no moving parts. Unless yours is really corroded with old coolant though........
As for ECM, you may be stuck with purchasing new one there. The supply of good used ones is rapidly dwindling. Repairing the old one, I'm not familiar with.
03-20-2008, 08:37 AM
#23
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That is B.S.
Just buy the new IACV like P.Samson has advised. In fact, I have personally installed only the new stepper motor from the IACV assembly to fix an issue. It is the only thing that is really necessary, since the remainder of the assembly has no moving parts. Unless yours is really corroded with old coolant though........
As for ECM, you may be stuck with purchasing new one there. The supply of good used ones is rapidly dwindling. Repairing the old one, I'm not familiar with.
Just buy the new IACV like P.Samson has advised. In fact, I have personally installed only the new stepper motor from the IACV assembly to fix an issue. It is the only thing that is really necessary, since the remainder of the assembly has no moving parts. Unless yours is really corroded with old coolant though........
As for ECM, you may be stuck with purchasing new one there. The supply of good used ones is rapidly dwindling. Repairing the old one, I'm not familiar with.
Thank you.
03-20-2008, 10:19 AM
#24
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After checking myself, the IACV (and TPS) are still replaceable units so I have no idea why the dealer that you are talking to is giving you that bull. Make sure that you get the correct ECM. There is an '01 and 1/2 PN listed for the Infiniti (as well as well as all the other standard PN variations), which I think is the 227 HP "Sport" version (the equivalent to the Maxi AE). Do you have the I30 Sport? As oldngivout suggested you could just swap out the stepper motor and pintle which would also save you having to remove the TB. Just make damn sure that the IACV housing has no signs of coolant leakage, and that the pintle seat is in good condition, and clean out any dirt/debris/scunge.
03-20-2008, 11:34 AM
#25
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Posts: 43
After checking myself, the IACV (and TPS) are still replaceable units so I have no idea why the dealer that you are talking to is giving you that bull. Make sure that you get the correct ECM. There is an '01 and 1/2 PN listed for the Infiniti (as well as well as all the other standard PN variations), which I think is the 227 HP "Sport" version (the equivalent to the Maxi AE). Do you have the I30 Sport? As oldngivout suggested you could just swap out the stepper motor and pintle which would also save you having to remove the TB. Just make damn sure that the IACV housing has no signs of coolant leakage, and that the pintle seat is in good condition, and clean out any dirt/debris/scunge.
OK I decided to look at my old original TB that caused all this trouble
I took some pics and probaly we can tell why it decided to stop working at 130K miles.
look at the pictures of it below in the link
http://www.box.net/shared/vmkpgdb8kw
So Dirty.
What do you think of this a leak?
http://www.box.net/shared/static/xt0xlwhogo.JPG
I found the TB with warranty for 240$ shipped I guess I will go with that and repair my own computer and put that in tow it to dealer and hopefully finish this dillema.
My car is I30 2001 w/TCS (not I30T)
Last edited by SEmy2K2go; 03-20-2008 at 01:11 PM.
03-20-2008, 12:29 PM
#26
Senior Member
Join Date: May 2004
Location: Vancouver, BC
Posts: 933
I would say that looks normal. Remove the two screws attaching the IACV motor and let's see inside the housing, and the pintle etc. I can see by the "witness sealing" that the TPS attach bolts and the throttle stop screw have never been disturbed, which I wondered about earlier.
Last edited by P. Samson; 03-20-2008 at 12:33 PM.
04-01-2008, 02:48 PM
#30
Junior Member
Join Date: Nov 2003
Posts: 43
sorry for not posting meanwhile and thanks for all the help.
long story short...
I had my ECM repaired and it comes now with one year warranty.
Now I have to make sure my IACV does not give me problem. the problem I had was openning the 2 screws that attach the IACV to the throttle body. but I opened it eventually and here are some pics of it.
my question: does my throttel body look okay? or do I have to change it?
I decided not to waste my time with a used IACV I buy it new from AutoZone for 220$.
I will clean my TB and use the new IACV on it.
please look at the pics and let me know if you think its cleanable or do I need to change the TB too...
the housing under the IACV looks dirty how can I clean that? or I just dont and it is fine or it is not fine?
All the pics are here in this folder:
http://www.box.net/shared/vmkpgdb8kw
Here is the housing under IACV.
Thank you!
long story short...
I had my ECM repaired and it comes now with one year warranty.
Now I have to make sure my IACV does not give me problem. the problem I had was openning the 2 screws that attach the IACV to the throttle body. but I opened it eventually and here are some pics of it.
my question: does my throttel body look okay? or do I have to change it?
I decided not to waste my time with a used IACV I buy it new from AutoZone for 220$.
I will clean my TB and use the new IACV on it.
please look at the pics and let me know if you think its cleanable or do I need to change the TB too...
the housing under the IACV looks dirty how can I clean that? or I just dont and it is fine or it is not fine?
All the pics are here in this folder:
http://www.box.net/shared/vmkpgdb8kw
Here is the housing under IACV.
Thank you!
04-01-2008, 07:11 PM
#31
Junior Member
Join Date: Nov 2003
Posts: 43
I guess I made a mistake the plastic part that I took off is not the IACV it is part of it. I just got back from Autozone, it is after market piece, I hope it is good.
the metal is also part of the IACV. so i guess I just have to clean the TB and should be fine. any input on the DuraLast brand from autozone. it sais made in Japan. I trust japan much better than china.
04-16-2008, 10:04 AM
#32
Junior Member
Join Date: Nov 2003
Posts: 43
Sorry to bother you and everyone else here.
Today for the 3rd time I changed the TB to a brand new one from dealer and the eCM also.. the problem is still there
I belive ther is a Wiring or Harness problem.. dont you think? what else could it be?
who could check it out for me?
http://forums.maxima.org/showthread....49#post6357049
I started a new post for this any input would be appreciated!
05-28-2008, 02:54 PM
#33
Senior Member
Join Date: Sep 2007
Location: Montreal (Canada)
Posts: 136
Sorry for bumping up this thread... 
The other day my car stalled at the drive thru at McD... it would start again but immediately die again (couldn't idle)... take it right away to my mechanic and came up with IACV problem... changed it
Now the car revs at 1500 rpm... what do I do?
My mechanic tried the Idle Learning procedure (not very familiar with it) but car still idling @ 1500 rpm's.
He told me to bring it to the stealership and have them do the Learning.
Could it also be that my ECU is fried (I read that this is very common when having a IACV issue), I didn't run with the car at all; only drove directly to the mechanic.
Any suggestions?
OH BTW, I have a 2000 Max GLE w/ auto trans.
Peter
The other day my car stalled at the drive thru at McD... it would start again but immediately die again (couldn't idle)... take it right away to my mechanic and came up with IACV problem... changed it
Now the car revs at 1500 rpm... what do I do?
My mechanic tried the Idle Learning procedure (not very familiar with it) but car still idling @ 1500 rpm's.
He told me to bring it to the stealership and have them do the Learning.
Could it also be that my ECU is fried (I read that this is very common when having a IACV issue), I didn't run with the car at all; only drove directly to the mechanic.
Any suggestions?
OH BTW, I have a 2000 Max GLE w/ auto trans.
Peter
05-28-2008, 03:12 PM
#34
Junior Member
Join Date: Nov 2003
Posts: 43
Sorry for bumping up this thread...
The other day my car stalled at the drive thru at McD... it would start again but immediately die again (couldn't idle)... take it right away to my mechanic and came up with IACV problem... changed it
Now the car revs at 1500 rpm... what do I do?
My mechanic tried the Idle Learning procedure (not very familiar with it) but car still idling @ 1500 rpm's.
He told me to bring it to the stealership and have them do the Learning.
Could it also be that my ECU is fried (I read that this is very common when having a IACV issue), I didn't run with the car at all; only drove directly to the mechanic.
Any suggestions?
OH BTW, I have a 2000 Max GLE w/ auto trans.
Peter
The other day my car stalled at the drive thru at McD... it would start again but immediately die again (couldn't idle)... take it right away to my mechanic and came up with IACV problem... changed it
Now the car revs at 1500 rpm... what do I do?
My mechanic tried the Idle Learning procedure (not very familiar with it) but car still idling @ 1500 rpm's.
He told me to bring it to the stealership and have them do the Learning.
Could it also be that my ECU is fried (I read that this is very common when having a IACV issue), I didn't run with the car at all; only drove directly to the mechanic.
Any suggestions?
OH BTW, I have a 2000 Max GLE w/ auto trans.
Peter
you can find out by driving it for 6 miles and come up with engine light and P0505
at that stage easy way is take it to a dealer with a better price and change the ECM and reprogram it. no need to change the TB if it new but if that is used then there is no guarantee what the problem is
Honestly I would call around and find the exact car go to junk yard and make sure the car runs perfect with no engine light.. buy the ECM , and TB from them (even the antena around the switch to avoid dealer ship due to imobalizer)
have your mechanic install them TB is around 40-70$ installation
ECM you can do it your self just a plug in and out with 4 screws I guess
the antena for switch I didnt change so not sure
I changed those and towed the car to dealer had reprogram it for 100-180$
and you are done
If you dont follow what I said exactly probably you will end up spending over 2000$ and a month or 2 of your life on this. depending how lucky or not you are .
again this can be solved by a simple 100 ECM from a junk yard and a reprograming or you might need to go expensive.. depending how lucky you are finding good parts with good price from junky or Dealer
Gluck and I promise my next car 99% wont be a nissan or infiniti
either Toyota or lexus
, I'm in Montreal (Canada).
11-15-2008, 11:12 PM
#36
Newbie - Just Registered
Join Date: Dec 2004
Posts: 4
I have the same problem as Dataman after changing iac valve :
--The car turns on and starts fine.
-The car idles at around 1700-2000 rpm at "N"
-When the car is cold it idles smooth but once it gets warmed up in a min or so it goes wild. it is as if the computer is trying to learn or is trying different settings, the RPM rapidly goes up and down. The car sounds like a child is playing with the Gas pedal.
I have a used ECM, as one dealer explained that the burnt IACV shorted out my ECM , although a second Nissan dealership mecanic did not think so ??! .When I install it the car will not start, but turns over just fine.
IACV was new, did a modified idle re-learn as instructed by 2nd dealer, but not as described in this thread- this I am going to try this one tomorow-
Does anyone have more info on the subject.
--The car turns on and starts fine.
-The car idles at around 1700-2000 rpm at "N"
-When the car is cold it idles smooth but once it gets warmed up in a min or so it goes wild. it is as if the computer is trying to learn or is trying different settings, the RPM rapidly goes up and down. The car sounds like a child is playing with the Gas pedal.
I have a used ECM, as one dealer explained that the burnt IACV shorted out my ECM , although a second Nissan dealership mecanic did not think so ??! .When I install it the car will not start, but turns over just fine.
IACV was new, did a modified idle re-learn as instructed by 2nd dealer, but not as described in this thread- this I am going to try this one tomorow-
Does anyone have more info on the subject.
11-16-2008, 05:21 AM
#37
Junior Member
Join Date: Nov 2003
Posts: 43
I have the same problem as Dataman after changing iac valve :
--The car turns on and starts fine.
-The car idles at around 1700-2000 rpm at "N"
-When the car is cold it idles smooth but once it gets warmed up in a min or so it goes wild. it is as if the computer is trying to learn or is trying different settings, the RPM rapidly goes up and down. The car sounds like a child is playing with the Gas pedal.
I have a used ECM, as one dealer explained that the burnt IACV shorted out my ECM , although a second Nissan dealership mechanic did not think so ??! .When I install it the car will not start, but turns over just fine.
IACV was new, did a modified idle re-learn as instructed by 2nd dealer, but not as described in this thread- this I am going to try this one tomorow-
Does anyone have more info on the subject.
--The car turns on and starts fine.
-The car idles at around 1700-2000 rpm at "N"
-When the car is cold it idles smooth but once it gets warmed up in a min or so it goes wild. it is as if the computer is trying to learn or is trying different settings, the RPM rapidly goes up and down. The car sounds like a child is playing with the Gas pedal.
I have a used ECM, as one dealer explained that the burnt IACV shorted out my ECM , although a second Nissan dealership mechanic did not think so ??! .When I install it the car will not start, but turns over just fine.
IACV was new, did a modified idle re-learn as instructed by 2nd dealer, but not as described in this thread- this I am going to try this one tomorow-
Does anyone have more info on the subject.
I remember what a pain was this problem..
I tried to economic and bought stuff from junk yard and changed them maybe 3-4 times till I bought BRAND NEW Computer and TB Assembly and had it changed by a mechanic and then towed the car to dealer for the expensive programing. it cost me easily $2500 and a lot of TIME!
do not trust the refurbished computers either.... I tried 2 of them from auto computer repair companies...
unless you have an unimaginable patience do as what I said with brand new stuff.
then sell this stupid car an go with toyota...
it is funny once I fixed the issue , out of pocket goes 2700$ and lots of my time... the stupid ABS+ SLIP+BRAKE light came on changed the ABS sensor 300$ and still the same...
Now I became one of those who uses white out on the engine light and just cant wait for a nice thief to steal this from me so I can get my money and buy a toyota.
ok I rambled a lot but I went through a hell with Infiniti/Maxima. My wife's corolla works so much cheaper and nicer even with 100K on it!
11-16-2008, 06:01 AM
#38
Does anyone have a pics of the ECM, my cousin is having the same issue with PO 505. I have replace the TPS and at cold start the car wouldn't start on the first try and after giving a little gas then it would idle correctly. For the one who are experiencing the idle going crazy like up and down, your IAC is the culprit and need to be replace. When I first replace it I only disconnected the battery replace the IAC and erase the code with my OBDII consol, the code never cam back and car was driving fine. Yesterday I replaced the TPS valve on the TB but the car behave the same as before, the car when cold would not idle properly and die. There is only 2 party that can go wrong on the TB , the TPS and IAC. I heard the problem might be the ECM so can anyone show me a pics of the 2k ECM and I'll investigate the problem further and report it back.
will post pic of spare ECM as soon as I can.