shiu

iTrader: (3)

Recently my max ( 2001 147K Auto ) had died on me and wouldn't start one morning. I checked the battery, starter and alternator but everything was fine. Left it alone and decided to figure it out on my day off. 2 days later after not driving the max, I decided to try to start it up again and after giving it some gas it fired up. I took it out for a drive and about 10 minutes later she stalled but would start back up immediately.

I had a mechanic come by to take a look at it and the code that came up was for a crank sensor. We replaced it and everything was fine for about a week until yesterday. I was driving as usual and took a left turn. I noticed right after the turn the RPM dropped to about 500 and felt as if the car was about to stall again. Right when I took my foot off the gas, my power steering failed and the max had stalled. I tried to start it back up but the highest RPM it would reach was 1 and would stall immediately after. I eventually got home by driving with 1 foot on the gas at all times and 1 foot on the brakes.

I haven't had any codes pulled yet as my mechanic is out of town for a couple of days but I suspect the problem would be the IACV. I read most ( if not all ) of the threads on here about IACV problems leading to frying ECU's and I'm worried thats the problem I'm dealing with.

My questions is..

Is it possible for me to install a used IACV and ECU from another max onto mine instead of just replacing the IACV and risking my ECU from frying?

Anyone else recently have this problem and had it fixed without frying the ECU?

shaks

iTrader: (15)

had similar issue - check maf and do an idle relearn procedure, also might consider cleaning TB
if you want to replace iacv (used one should come from max with approximately same manufacturing date) for more info search around here for iacv replacement. I know one guy in brooklyn on Neprune av, he does relearn for around 70 bucks, you can perform it by yourself but not always successfully.

NAVY00MAXIMA

The IdleAirControlValve can go bad in two different ways. The Hitachi electric stepper motor / IACV can die of age "naturally" -OR- the IACV body to throttle body gasket can fail and allow the stepper motor to come into contact with engine coolant and well. It shorts obviously and fries the ELECTRICAL circuit and well from there it CAN send the electrical mess to ECU and fry, short, kill or zap it... Did you get lucky? Replace the IACV and see.

NAVY00MAXIMA

The most important thing about replacing the IACV is to do the ENTIRE job. Most of those failed ECU's if not all came from only replacing the IACV's motor itself and not it's entire assembly and not repairing the leaking sealing surface that probably ruined it to begin with. (IT COMES IN ONE PIECE BUT THE IACV MOTOR IS QUITE SIMPLE AND CAN BE TAKEN OFF ITS HOUSING WITH 2 SCREWS AND TURNS THE JOB FROM A 1 HOUR JOB TO A 5 MINUTE JOB) Removing the throttle body to do the job right is simpler than you would assume. Cleaning the TB ought to take the most of your time

Specd_out

Just something i figured i would share with you guys regarding the IACV. If you are worried about coolant shorting out the IACV you can do a throttle body bypass.

Basicly from the factory nissan pushes hot coolant through the throttle body to keep it a similar temp as the IM which gets warm from contact with the head. I am figuring its to prevent warping and cracking of the IM or tb due to the different expansion rates of the metal. Anyway Its a utterly useless and potentially power robbing design. the sentra community has been doing this bypass since the QR (which has a very similar designed TB) came out. The only issue is if you live in frigged areas where having the throttle body warmed may be needed. We have members from WI and NY that have had this bypass done with no issues. I live in fl and have had it done for nearly 8 years.

Long story short removing the TB from the coolant circuit will prevent coolant from coming near the IACV thereby completely removing any threat of a leaky gasket.

NAVY00MAXIMA

Yes.. IACV coolant bypass is an option but it is how it is for a reason. I tried bypassing mine but on start-up I knew it wasnt right. The IACV is sensitive...

Specd_out

i understand that but the reason is so that the car can be sold in all of north America with minimum modification due to climate. most of us wont ever have any issues. I bypassed my maxima, about a week after i bought it and my sentras been that way for about 8 years. both cars use a hitachi TB and IACV

sticky

i have same problem had ecu rebuilt,new iacv,new tps,disconnect motor mount,idles perfect 700 give it gas goes to 1800 and starts surging up and down let off goes right to 700 i cant figure it out

NAVY00MAXIMA

Will the engine not rev over 1,800 RPM's?

sticky

no it will not go over 1800rpm

NAVY00MAXIMA

Checked the MassAirFlowSensor?

sticky

just replaced no change im stumped

sticky

hey specd out can you tell a change when you bypassed,what do you do run the water lines back together and cap off the two inlets on the iacv

sticky

ok when now when start up it will go to 3200 rpm and surge up and down,when warm it will only go to 1800 rpm with surge,im going to keep trying relearn today

viking1

I actually have an even weirder variation of this problem after running sea foam thru the car. Engine wont rev past 1800 rpm unless I disconnect the TPS (which is new x 2); then it idles high (1100 rpm in neutral; 1800 in gear) but runs normally. I've changed the knock sensor, reset the ECU by disconnecting the battery, and cleaned the IACV to no avail. Any ideas? Thx :-)

MichMaxFan

We have to do the idle relearn thingy after a tb removal, correct? What makes some of them unsuccessful? I don't want to have to pay the stealer.

Also, are our cars like the old "Christine" movie? How on earth does it know that something was removed and put back??? Geeshh..we are being watched!!

Rods03Max619

iTrader: (5)

Might have to pay the Stealership tomorrow to reprogram my car since after engine swap it seems good 20 and up but off the line like wtf...and get my timing bumped up to 17* degrees since paying already...

doublea

iTrader: (7)

Can someone just could be more specific on the coolant bypass ? Do you just unplug the 2 coolant lines from the IACV, block the hose and call it a day. I wont be driving my maxima on winter anymore. My ECU is fried, I ordered the STA590A chip and going to fix the ECU but how does the idle is set without the coolant going thrue IACV ?

xspanishxkidx

iTrader: (1)

http://forums.maxima.org/5th-generat...nt-bypass.html

doublea

iTrader: (7)

Ok thanks, the plate is cool to have since spring morning can be cooler.

4th gen maxi

iTrader: (1)

dont think you should do that.. i have the same prob. waiting on sum cash to ree up on parts. we both mostlikely need rebuild ecu and new iacv. im shipping mine as soon as money good..