Weird issue at idle and cruising! Not the common one you always see. Please read!
May 17, 2009, 05:34 PM
#1
Weird issue at idle and cruising! Not the common one you always see. Please read!
All,
I am running a very weird situation with the car’s idle/cruise and before I start a thread about it, I collected some data to provide enough info to see if I can get to the root cause. Please note that this happened at the same time the original ECU was overheating coil pack 1 (1&4) and had to replace it with a new one. So, let’s break it down.
Setup: In my signature and using a COP and IKH24 sparks. PTE 780. FPRed already in.
Symptoms: The car idle is running VERY rich (10s and 9s) after a throttle lift-off idle and while hitting the gas pedal just to break the butterfly inside the TB. The TPS sits around 13.333% closed, so it will happen at only 20-25% of the TPS at cruising. The AFRs are back to normal (14sand 15s) after I press the pedal just a bit more.
However, if I start the car after it has been sitting for a while, the car will idle just fine with AFRs around 14-15s. But it is back to super rich in the formentioned areas after a few minutes of me driving it.
So, the real problem is that once the car is in closed loop, the car’s trims are thrown off to very negative regardless of the latencies and scaling I use. Even if they are extreme based on what I used to use in the past which BTW never had a problem. At the end, the car when it is not under the pig rich condition will run cruising super lean 16.9 because the trims are so negative and it will run pig rich again after I let it idle. Sometimes throwing the P0172 code (System pig rich). That erratic going pig rich at idle and while tipping the gas pedal while cruising is what is tricking the ECU to believe that it is running too rich and start pulling gas with the trims… once the car is not doing the super rich conditions runs very lean causing a very rough cruising.
See video here:
This is what the car will do until it reaches cruise trim @ -12 and start acting up.
Troubleshooting:
1. I used good sparks (IKH24). Ordered a new set just to be sure. They are gapped to 0.020.
2. The same symptoms occur with the OEM ignition system and my CDI COP.
3. Boost leak- none found. Shaft seals from Aby are holding boost fine.
4. Used different injector scalings from 688 to 750 and about all of the latencies in the vicinity of 0.790 +/- 0.10 @ 14 volts. All resulting at the end to what it was described.
5. Disabled closed loop (thanks mrfred) in the ECU just to make sure that the behavior I am describing resembles/supports my theory at the end. Just wanted to see what the AFRs are w/o the ECU adjusting the mixture. That is actually how I found what was happening.
6. No misfiring at WOT and AFRs are consistent during pulls.
7. Checked TPS, MAP, MAF sensors.
8. Tried rescaling the MAF with no avail.
This is what I think the cause is:
I think that whatever messed up the ECU might have messed up one injector or all them. UPDATE: DIscard this one as I tested the car with a good known set of injectors and the car is experiencing the same problem.
I just can not think off anything else may have been causing this problem and I am open to any suggestions. BTW, sorry for the long post!
I am running a very weird situation with the car’s idle/cruise and before I start a thread about it, I collected some data to provide enough info to see if I can get to the root cause. Please note that this happened at the same time the original ECU was overheating coil pack 1 (1&4) and had to replace it with a new one. So, let’s break it down.
Setup: In my signature and using a COP and IKH24 sparks. PTE 780. FPRed already in.
Symptoms: The car idle is running VERY rich (10s and 9s) after a throttle lift-off idle and while hitting the gas pedal just to break the butterfly inside the TB. The TPS sits around 13.333% closed, so it will happen at only 20-25% of the TPS at cruising. The AFRs are back to normal (14sand 15s) after I press the pedal just a bit more.
However, if I start the car after it has been sitting for a while, the car will idle just fine with AFRs around 14-15s. But it is back to super rich in the formentioned areas after a few minutes of me driving it.
So, the real problem is that once the car is in closed loop, the car’s trims are thrown off to very negative regardless of the latencies and scaling I use. Even if they are extreme based on what I used to use in the past which BTW never had a problem. At the end, the car when it is not under the pig rich condition will run cruising super lean 16.9 because the trims are so negative and it will run pig rich again after I let it idle. Sometimes throwing the P0172 code (System pig rich). That erratic going pig rich at idle and while tipping the gas pedal while cruising is what is tricking the ECU to believe that it is running too rich and start pulling gas with the trims… once the car is not doing the super rich conditions runs very lean causing a very rough cruising.
See video here:
This is what the car will do until it reaches cruise trim @ -12 and start acting up.
Troubleshooting:
1. I used good sparks (IKH24). Ordered a new set just to be sure. They are gapped to 0.020.
2. The same symptoms occur with the OEM ignition system and my CDI COP.
3. Boost leak- none found. Shaft seals from Aby are holding boost fine.
4. Used different injector scalings from 688 to 750 and about all of the latencies in the vicinity of 0.790 +/- 0.10 @ 14 volts. All resulting at the end to what it was described.
5. Disabled closed loop (thanks mrfred) in the ECU just to make sure that the behavior I am describing resembles/supports my theory at the end. Just wanted to see what the AFRs are w/o the ECU adjusting the mixture. That is actually how I found what was happening.
6. No misfiring at WOT and AFRs are consistent during pulls.
7. Checked TPS, MAP, MAF sensors.
8. Tried rescaling the MAF with no avail.
This is what I think the cause is:
I think that whatever messed up the ECU might have messed up one injector or all them. UPDATE: DIscard this one as I tested the car with a good known set of injectors and the car is experiencing the same problem.
I just can not think off anything else may have been causing this problem and I am open to any suggestions. BTW, sorry for the long post!
Last edited by joedr; Sep 1, 2009 at 08:15 PM.
May 17, 2009, 05:46 PM
#2
Are these new injectors? What are your fuel trims? what about lowering the latency value at 14v and see if you get a hold of the rich condition?
Last edited by oldevodude; May 17, 2009 at 05:48 PM.
May 17, 2009, 06:00 PM
#3
The injectors have been in the car for the past year or so. Just before the ECU fried incident, I was able to get the trims up to +/- 2.
Right now, no matter what scalings or latencies I use... the car will end up with idle -4 and cruise around -12. In a few days, the car will throw P0172 and at that time the car is almost undriveable at cruise due to the very lean conditions during cruise unless I hammer the gas pedal forcing the car to get out of closed loop.
In order to get the car driveable again, I have to reset the trims whih will make the car fine for a day or so. In a few days, the trims will go back to ~-4 and -12. That is what got me to think that may be something related to the injection system.
Right now, no matter what scalings or latencies I use... the car will end up with idle -4 and cruise around -12. In a few days, the car will throw P0172 and at that time the car is almost undriveable at cruise due to the very lean conditions during cruise unless I hammer the gas pedal forcing the car to get out of closed loop.
In order to get the car driveable again, I have to reset the trims whih will make the car fine for a day or so. In a few days, the trims will go back to ~-4 and -12. That is what got me to think that may be something related to the injection system.
Last edited by joedr; May 17, 2009 at 06:03 PM.
May 17, 2009, 07:48 PM
#5
Huuum! You know what? I am not sure I still have them... well I do not remember where are they?
Well! The long story short is that while swapping the green for the red, I used a battery maintainer (never used it while the battery was still on the car... only with batteries outside the car) to not let the battery died. I had to travel in the middle of the turbo swap and the red did not arrive home on time. It took me two months to complete the swap.
When I fired the car up, the car was feeling weird and felt as if two cylinders were not firing. I checked the coils and coil 1&4 was overheated. After some tests, I found a buddy with a spare 9 ECU and found that the ECU was causing the overheating.
After that incident, the car has not been the same at idle/cruise. I scaled many injectors on EVOs and Hondas.... even with far more modded cars than mine and this is driving me crazy. The car pulls very good, it just that after a few days of adjusting itself... it will become a PITA to drive around the neighborhood hesitating, sputtering and stalling.
Well! The long story short is that while swapping the green for the red, I used a battery maintainer (never used it while the battery was still on the car... only with batteries outside the car) to not let the battery died. I had to travel in the middle of the turbo swap and the red did not arrive home on time. It took me two months to complete the swap.
When I fired the car up, the car was feeling weird and felt as if two cylinders were not firing. I checked the coils and coil 1&4 was overheated. After some tests, I found a buddy with a spare 9 ECU and found that the ECU was causing the overheating.
After that incident, the car has not been the same at idle/cruise. I scaled many injectors on EVOs and Hondas.... even with far more modded cars than mine and this is driving me crazy. The car pulls very good, it just that after a few days of adjusting itself... it will become a PITA to drive around the neighborhood hesitating, sputtering and stalling.
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May 18, 2009, 12:18 AM
#8
Hi!
I tried scaling the MAF and no matter how much I tried to pull gas on those load cells 50-100, the car will end up with very negative trims and the super rich condition persisted after TB lift-off. It was worst because now the ECU will pull more gas due to trims and with a "tuned" maf that is making it leaner. The car will become very harsh during cruise until I get P0172. Something is throwing off the injectors or the correct combustion during idle/cruise and I have not been able to find it.
I always had the BR intake andnever had this type of problem. Before this turbo swap, I rebuilt the engine completely, tested a few sets of cams and ran with another TBE and always able to dialed injectors w/o touching the maf.
The car made 403 at 24 PSI and it was driving like a stocker. After the turbo swap and the ECU incident, the car has experienced this.
I tried scaling the MAF and no matter how much I tried to pull gas on those load cells 50-100, the car will end up with very negative trims and the super rich condition persisted after TB lift-off. It was worst because now the ECU will pull more gas due to trims and with a "tuned" maf that is making it leaner. The car will become very harsh during cruise until I get P0172. Something is throwing off the injectors or the correct combustion during idle/cruise and I have not been able to find it.
I always had the BR intake andnever had this type of problem. Before this turbo swap, I rebuilt the engine completely, tested a few sets of cams and ran with another TBE and always able to dialed injectors w/o touching the maf.
The car made 403 at 24 PSI and it was driving like a stocker. After the turbo swap and the ECU incident, the car has experienced this.
May 18, 2009, 01:01 AM
#10
Hi!
I tried scaling the MAF and no matter how much I tried to pull gas on those load cells 50-100, the car will end up with very negative trims and the super rich condition persisted after TB lift-off. It was worst because now the ECU will pull more gas due to trims and with a "tuned" maf that is making it leaner. The car will become very harsh during cruise until I get P0172. Something is throwing off the injectors or the correct combustion during idle/cruise and I have not been able to find it.
I always had the BR intake andnever had this type of problem. Before this turbo swap, I rebuilt the engine completely, tested a few sets of cams and ran with another TBE and always able to dialed injectors w/o touching the maf.
The car made 403 at 24 PSI and it was driving like a stocker. After the turbo swap and the ECU incident, the car has experienced this.
I tried scaling the MAF and no matter how much I tried to pull gas on those load cells 50-100, the car will end up with very negative trims and the super rich condition persisted after TB lift-off. It was worst because now the ECU will pull more gas due to trims and with a "tuned" maf that is making it leaner. The car will become very harsh during cruise until I get P0172. Something is throwing off the injectors or the correct combustion during idle/cruise and I have not been able to find it.
I always had the BR intake andnever had this type of problem. Before this turbo swap, I rebuilt the engine completely, tested a few sets of cams and ran with another TBE and always able to dialed injectors w/o touching the maf.
The car made 403 at 24 PSI and it was driving like a stocker. After the turbo swap and the ECU incident, the car has experienced this.
I understand you had the intake on before without problems, but I'm just trying to help with what I know
Have you tried putting back the stock injectors/scaling/and latency settings and seeing if that bring your trims/idle back to normal? That would rule out alot of stuff.
May 18, 2009, 06:15 AM
#12
If im not mistaken, you need to get the trims within +\- 5 at cruise and idle before you scale the maf. You shouldn't need to touch your fuel map at all, if the car has the proper latencies and trims in line, closed loop should take care of staying at 14.7 stoich. Specifically since you said it is only during idle/cruise, this is when closed loop is in effect. I agree, the problem so far is that the trims are going negative (Cruise to -12) no matter what I do.
I understand you had the intake on before without problems, but I'm just trying to help with what I know I appreciate everyones comments and appreciate that you take your time to respond with ideas. Thanks a lot buddy! 
Have you tried putting back the stock injectors/scaling/and latency settings and seeing if that bring your trims/idle back to normal? That would rule out alot of stuff. I aggree! Let me look this afternoon for the injectors to test if the car continues to do that after swapping a good set of Injectors with known good latencies.
I understand you had the intake on before without problems, but I'm just trying to help with what I know
I appreciate everyones comments and appreciate that you take your time to respond with ideas. Thanks a lot buddy! Have you tried putting back the stock injectors/scaling/and latency settings and seeing if that bring your trims/idle back to normal? That would rule out alot of stuff. I aggree! Let me look this afternoon for the injectors to test if the car continues to do that after swapping a good set of Injectors with known good latencies.
May 18, 2009, 06:22 AM
#13
Huuuuuum! I swapped the LICP for a BR that does not have the nipple to sourced the BOV (which is recirculated) and had to use the line that is sourcing the Electronic Boost Controller. I am using a Blitz iColor and the actuator is a dual solenoid.
I did that change before swapping the red and was working fine if my memory does not fail. However, I may be wrong!
I did that change before swapping the red and was working fine if my memory does not fail. However, I may be wrong!
May 18, 2009, 08:56 AM
#14
well, if you are running fine in open loop it sounds like it can only be 1 of 3 things:
-giant air leak (should cause rich instead of lean).
-Tuning issues / you are repeatedly messing up something in the rom (unlikely, but you could have screwed something up. Start with a fresh rom and only change your injector scaling and latency, see if the same thing still happens)
-O2 feedback / narrowband sensor dying. Seems like the most likely culprit, no?
-giant air leak (should cause rich instead of lean).
-Tuning issues / you are repeatedly messing up something in the rom (unlikely, but you could have screwed something up. Start with a fresh rom and only change your injector scaling and latency, see if the same thing still happens)
-O2 feedback / narrowband sensor dying. Seems like the most likely culprit, no?
May 18, 2009, 08:57 AM
#15
Huuuuuum! I swapped the LICP for a BR that does not have the nipple to sourced the BOV (which is recirculated) and had to use the line that is sourcing the Electronic Boost Controller. I am using a Blitz iColor and the actuator is a dual solenoid.
I did that change before swapping the red and was working fine if my memory does not fail. However, I may be wrong!
I did that change before swapping the red and was working fine if my memory does not fail. However, I may be wrong!
Also, since you just changed to a Buschur LICP, what other parts did you just recently change?
If the car is going super rich, with negative trims, then to me that sounds like either (a) the MAF is telling the ECU there is more air entering than there is, (b) all of the metered air isn't reaching the cylinders because of a vacuum/boost leak somewhere (maybe BOV issue), or (c) like you mentioned, something really wrong with your injectors.
I would tend to lean towards a or b, mostly b, especially if you just changed some parts and vacuum lines/routing. Make sure your BOV is connected properly and all lines that you have just changed are secure and not leaking.
