Fuel pump wiring - Tell me if this is wrong......
11-14-2003, 07:56 AM
#1
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Fuel pump wiring - Tell me if this is wrong......
hi all...
this is for the SC kit...
instead of using Stillen's relay and vacuum switch to power and regulate the inline pump....the power wire is tapped to the power wire of the MAF sensor. Can this affect the pump performance? can this be the cause of my lean nightmare?
thx
this is for the SC kit...
instead of using Stillen's relay and vacuum switch to power and regulate the inline pump....the power wire is tapped to the power wire of the MAF sensor. Can this affect the pump performance? can this be the cause of my lean nightmare?
thx
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11-14-2003, 09:20 AM
#2
Originally Posted by IceY2K1
I get nervous when guys start tapping random power wires ESPECIALLY the MAF withOUT a relay! You never tap something critical like the MAF and use it strictly as your power source for some aux device. You can do this if you need it to only be turned on whenever the MAF is being heated, but you MUST use a relay to isolate it. Run a fused power wire DIRECTLY off the battery and use the MAF tap or something better like a rear 02 or any ignition switched device, to switch the relay on/off NOT the fuel pump.
Only reason the MAF should EVER get tapped is for a S-AFC.
It's DEFINITELY NOT a suitable power source, however I don't know if it's causing your problems or not.
it wanst me
so the story was....
my first dyno in march - car was lean and pump was off. They did a qucik fix and hook up the fuel pump to the MAF and it was running fine. I got a rich AFR on my last 2 runs of the day and went home happy.
the recent dyno - car's lean again and the AFR is 14:1....you know this part of the story.
so....can the pump be damage when hooking up to the MAF? or the MAF voltage reading gets really messed up and the car thinks that I am getting less air during boost so it adjusts the fuel accordingly to compensate?
I am going to correct this this weekend. I will first try to hook up the pump straight off the battery and see the lean problem gets resolved. if so, I will rewire everything and get the relay/vacuum switch to work.
hope I can end it this weekend.
11-14-2003, 09:29 AM
#3
Per FSM:
The mass air flow sensor is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a hot wire that is supplied with electric current from the ECM. The temperature of the hot wire is controlled by the ECM a certain amount. The heat generated by the hot wire is reduced as the intake air flows around it. The more air, the
greater the heat loss. Therefore, the ECM must supply more electric current to maintain the temperature of the hot wire as air flow increases. The ECM detects the air flow by means of this current change.
So, now you're actually STEALING power from the MAF(depending on which wire) and the ECU could not be seeing the increased air thus not adding fuel and you're running lean.
Dixit has the MAF all figured, so find out WHICH power wire you tapped to the MAF.
The mass air flow sensor is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a hot wire that is supplied with electric current from the ECM. The temperature of the hot wire is controlled by the ECM a certain amount. The heat generated by the hot wire is reduced as the intake air flows around it. The more air, the
greater the heat loss. Therefore, the ECM must supply more electric current to maintain the temperature of the hot wire as air flow increases. The ECM detects the air flow by means of this current change.
So, now you're actually STEALING power from the MAF(depending on which wire) and the ECU could not be seeing the increased air thus not adding fuel and you're running lean.
Dixit has the MAF all figured, so find out WHICH power wire you tapped to the MAF.
11-14-2003, 09:34 AM
#4
According to my FSM for a 2001:
R/G = 12V
R = 5V
W = 1.2V-1.8V(idle/warm-up), 1.6V-2.2V(2,500rpm under warm-up)
So, you must have the Red/Green wire tapped to supply power to the aux fuel pump.
I'm thinking that the aux fuel pump draw on the 12V supply wire causes the MAF sensor to misrepresent the amount of airflow you're seeing.
Sounds possible to me.
R/G = 12V
R = 5V
W = 1.2V-1.8V(idle/warm-up), 1.6V-2.2V(2,500rpm under warm-up)
So, you must have the Red/Green wire tapped to supply power to the aux fuel pump.
I'm thinking that the aux fuel pump draw on the 12V supply wire causes the MAF sensor to misrepresent the amount of airflow you're seeing.
Sounds possible to me.
11-14-2003, 10:39 AM
#6
Ok...I think I'm on to something here:
Mixture Ratio Self-learning Control
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxygen sensor 1 (front). This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes during operation (i.e., injector clogging) directly affect mixture ratio. Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is then computed in terms of “injection pulse duration” to automatically compensate for the difference between the two ratios.
Now when I ORIGINALLY read this I thought it was referring to the CLOSED-LOOP feed back, since it starts with "mixture ratio feedback control system", but that wouldn't apply to you since you're clearly open-loop at WOT on the dyno. However, now that I read it carefully, I believe this is an ENTIRELY different system then either the closed-loop or open-loop control system and may very well be the problem you're causing by screwing with the MAF supply voltage PLUS what the current 2K2+ Stillen header guys are running into with 02-simulators.
Sorry thinking a bit out loud here, so I don't forget to put all this in the Stillen header threads.
Mixture Ratio Self-learning Control
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxygen sensor 1 (front). This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes during operation (i.e., injector clogging) directly affect mixture ratio. Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is then computed in terms of “injection pulse duration” to automatically compensate for the difference between the two ratios.
Now when I ORIGINALLY read this I thought it was referring to the CLOSED-LOOP feed back, since it starts with "mixture ratio feedback control system", but that wouldn't apply to you since you're clearly open-loop at WOT on the dyno. However, now that I read it carefully, I believe this is an ENTIRELY different system then either the closed-loop or open-loop control system and may very well be the problem you're causing by screwing with the MAF supply voltage PLUS what the current 2K2+ Stillen header guys are running into with 02-simulators.
Sorry thinking a bit out loud here, so I don't forget to put all this in the Stillen header threads.
11-14-2003, 11:15 AM
#7
let see if I am following you.
so this mixture ratio self learning thingy will supercede the open loop control?
so the MAF gets a messed up reading and thus it tells the ECU that not enough air is read. The ECU then alters the injector pulse duration and lower the duty cycle of the injector in order to compensate the "less air" measured. The fuel pressure reading may be accurate, pump may be working. I mean, all the mechanical parts are working properly. But the fuel is just not getting in to the engine because the MAF is getting a false reading and the injectors are adjusterd accordingly?
since it is a self learning program that means it will get the mixture raito to the most suitable number for NA (since the ECU never know that she's supercharged), that's why I have a flat and smooth lean AFR. I think this also explains why I have rich runs right after tapping the fuel pump to the MAF power wire.....because it hasnt learned and adjusted to the "new MAF reading"
just want to make sure that I am on the same page with you.
thx
so this mixture ratio self learning thingy will supercede the open loop control?
so the MAF gets a messed up reading and thus it tells the ECU that not enough air is read. The ECU then alters the injector pulse duration and lower the duty cycle of the injector in order to compensate the "less air" measured. The fuel pressure reading may be accurate, pump may be working. I mean, all the mechanical parts are working properly. But the fuel is just not getting in to the engine because the MAF is getting a false reading and the injectors are adjusterd accordingly?
since it is a self learning program that means it will get the mixture raito to the most suitable number for NA (since the ECU never know that she's supercharged), that's why I have a flat and smooth lean AFR. I think this also explains why I have rich runs right after tapping the fuel pump to the MAF power wire.....because it hasnt learned and adjusted to the "new MAF reading"
just want to make sure that I am on the same page with you.
thx
Originally Posted by IceY2K1
Ok...I think I'm on to something here:
Mixture Ratio Self-learning Control
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxygen sensor 1 (front). This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes during operation (i.e., injector clogging) directly affect mixture ratio. Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is then computed in terms of “injection pulse duration” to automatically compensate for the difference between the two ratios.
Now when I ORIGINALLY read this I thought it was referring to the CLOSED-LOOP feed back, since it starts with "mixture ratio feedback control system", but that wouldn't apply to you since you're clearly open-loop at WOT on the dyno. However, now that I read it carefully, I believe this is an ENTIRELY different system then either the closed-loop or open-loop control system and may very well be the problem you're causing by screwing with the MAF supply voltage PLUS what the current 2K2+ Stillen header guys are running into with 02-simulators.
Sorry thinking a bit out loud here, so I don't forget to put all this in the Stillen header threads.
Mixture Ratio Self-learning Control
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxygen sensor 1 (front). This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes during operation (i.e., injector clogging) directly affect mixture ratio. Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is then computed in terms of “injection pulse duration” to automatically compensate for the difference between the two ratios.
Now when I ORIGINALLY read this I thought it was referring to the CLOSED-LOOP feed back, since it starts with "mixture ratio feedback control system", but that wouldn't apply to you since you're clearly open-loop at WOT on the dyno. However, now that I read it carefully, I believe this is an ENTIRELY different system then either the closed-loop or open-loop control system and may very well be the problem you're causing by screwing with the MAF supply voltage PLUS what the current 2K2+ Stillen header guys are running into with 02-simulators.
Sorry thinking a bit out loud here, so I don't forget to put all this in the Stillen header threads.
11-14-2003, 11:40 AM
#8
Originally Posted by [maxi-overdose]
let see if I am following you.
so this mixture ratio self learning thingy will supercede the open loop control?
so this mixture ratio self learning thingy will supercede the open loop control?
Basically, MRSLC sounds like an algorithm to correct/compensate for parts such as the MAF and injectors(FSM specific examples) that deviate out of range over time due to age, contaminants, whatever. So, in your case, IF the MAF supply voltage is used as a "baseline" of sorts to which the ECU references its heating of the element, you've now changed that by adding the additional load of the aux fuel pump. At first, the aux fuel pumps' additional fuel pressure measures RICH on the dyno, however over time the MRSLC would see the draw your aux fuel pump has on the MAF as a deviation out of range and start leaning out the mixture. Why it would go lean vs. rich I'm not sure exactly, but I'd guess the 5V the ECU uses to hold constant across the element is based on an expected 12-14V supply that you've modified.
so the MAF gets a messed up reading and thus it tells the ECU that not enough air is read. The ECU then alters the injector pulse duration and lower the duty cycle of the injector in order to compensate the "less air" measured. The fuel pressure reading may be accurate, pump may be working. I mean, all the mechanical parts are working properly. But the fuel is just not getting in to the engine because the MAF is getting a false reading and the injectors are adjusterd accordingly?
since it is a self learning program that means it will get the mixture raito to the most suitable number for NA (since the ECU never know that she's supercharged), that's why I have a flat and smooth lean AFR. I think this also explains why I have rich runs right after tapping the fuel pump to the MAF power wire.....because it hasnt learned and adjusted to the "new MAF reading"
just want to make sure that I am on the same page with you.
11-14-2003, 03:24 PM
#9
so once I hook everything back up together, I should unplug my neg battery cable to flush the ECU? or I have to let the car the learn the new MAF readings.
I did that after my last dyno and let it sit over night to reset the ECU. next day it still runs the same.
thx
I did that after my last dyno and let it sit over night to reset the ECU. next day it still runs the same.
thx
11-14-2003, 03:43 PM
#10
Yes and try the Idle Air Volume Learning Procedure(withOUT a Consult part) to see if that makes a difference.
2K1 FSM states:
2K1 FSM states:
Idle Air Volume Learning
DESCRIPTION:
“Idle Air Volume Learning” is an operation to learn the idle air volume
that keeps each engine within the specific range. It must be
performed under any of the following conditions:
I Each time IACV-AAC valve, throttle body or ECM is replaced.
I Idle speed or ignition timing is out of specification.
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 WITH CONSULT-II, drive vehicle until “FLUID
TEMP SE” in “DATA MONITOR” mode of “A/T” system indicates
less than 0.9V.
For A/T models withOUT CONSULT-II and M/T models, drive
vehicle for 10 minutes.
OPERATION PROCEDURE With 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. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
8. Touch “START” and wait 20 seconds.
9. Make sure that “CMPLT” is displayed on CONSULT-II screen.
If “INCMP” is displayed, “Idle Air Volume Learning” will not be
carried out successfully. 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)
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 (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)
NOTE:
If idle air volume learning cannot be performed successfully,
proceed as follows:
1) Check that throttle valve is fully closed.
2) Check PCV valve operation.
3) Check that downstream of throttle valve is free from air
leakage.
4) Adjust closed throttle position switch and reset memory.
(Refer to Basic Inspection, EC-111.)
5) When the above three items check out OK, engine component
parts and their installation condition are questionable.
Check and eliminate the cause of the problem.
It is useful to perform “TROUBLE DIAGNOSIS — SPECIFICATION
VALUE”, EC-143.
6) If any of the following conditions occur after the engine
has started, eliminate the cause of the problem and perform
“Idle air volume learning” all over again:
I Engine stalls.
I Erroneous idle.
I Blown fuses related to the IACV-AAC valve system.
DESCRIPTION:
“Idle Air Volume Learning” is an operation to learn the idle air volume
that keeps each engine within the specific range. It must be
performed under any of the following conditions:
I Each time IACV-AAC valve, throttle body or ECM is replaced.
I Idle speed or ignition timing is out of specification.
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 WITH CONSULT-II, drive vehicle until “FLUID
TEMP SE” in “DATA MONITOR” mode of “A/T” system indicates
less than 0.9V.
For A/T models withOUT CONSULT-II and M/T models, drive
vehicle for 10 minutes.
OPERATION PROCEDURE With 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. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
8. Touch “START” and wait 20 seconds.
9. Make sure that “CMPLT” is displayed on CONSULT-II screen.
If “INCMP” is displayed, “Idle Air Volume Learning” will not be
carried out successfully. 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)
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 (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)
NOTE:
If idle air volume learning cannot be performed successfully,
proceed as follows:
1) Check that throttle valve is fully closed.
2) Check PCV valve operation.
3) Check that downstream of throttle valve is free from air
leakage.
4) Adjust closed throttle position switch and reset memory.
(Refer to Basic Inspection, EC-111.)
5) When the above three items check out OK, engine component
parts and their installation condition are questionable.
Check and eliminate the cause of the problem.
It is useful to perform “TROUBLE DIAGNOSIS — SPECIFICATION
VALUE”, EC-143.
6) If any of the following conditions occur after the engine
has started, eliminate the cause of the problem and perform
“Idle air volume learning” all over again:
I Engine stalls.
I Erroneous idle.
I Blown fuses related to the IACV-AAC valve system.
Originally Posted by [maxi-overdose]
so once I hook everything back up together, I should unplug my neg battery cable to flush the ECU? or I have to let the car the learn the new MAF readings.
I did that after my last dyno and let it sit over night to reset the ECU. next day it still runs the same.
thx
I did that after my last dyno and let it sit over night to reset the ECU. next day it still runs the same.
thx
11-17-2003, 08:17 AM
#11
Ice: update on this issue - still cant have the problem resolved. I rewired everything and it is going thru a fuse and relay. it is now tapped to the fuel relay and the pump is on all the time. I am still running on the old pump. I unplugged the neg cable of the battery and left it there entire night to reset the ECU. Today, I did couple runs on freeway and the EGT was still pretty high. 
I couldnt get over 100mph before the EGT reaches 800c, just like the same old day.
the only differences that I noticed is that the car does not backfire a lot like before....dunno if it is related at all.
and I havent tried the idle air volume learning.
I couldnt get over 100mph before the EGT reaches 800c, just like the same old day. the only differences that I noticed is that the car does not backfire a lot like before....dunno if it is related at all.
and I havent tried the idle air volume learning.
11-17-2003, 10:15 AM
#12
as for now....I will replace the pump. if it doesnt work, then I have to look into something that monitors the injector. something simple like the one that Stephen max has or an S-AFC if Santa brought me one. 
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