1JZ Running Rich: Bad ECU Capacitor?
08-28-13, 10:27 AM
#1
1JZ Running Rich: Bad ECU Capacitor?
Sup guys?
1JZ VVTI. Stock ECU w/ SAFC.
On the way to work this morning, car ran just fine for 5 mins (could boost and normal AFR).
Then all of a sudden, under part throttle, the car ran rich (10.0 flat AFR) and felt really slow (no bogging or anything).
Release the throttle, AFR went back to perfectly stoich (14.7 to 15.2) and idled the same way.
Checked all the lines under the hood and they were fine.
Could it be bad ECU capacitors? I just want to make sure before I start opening the box.
Thanks,
David
1JZ VVTI. Stock ECU w/ SAFC.
On the way to work this morning, car ran just fine for 5 mins (could boost and normal AFR).
Then all of a sudden, under part throttle, the car ran rich (10.0 flat AFR) and felt really slow (no bogging or anything).
Release the throttle, AFR went back to perfectly stoich (14.7 to 15.2) and idled the same way.
Checked all the lines under the hood and they were fine.
Could it be bad ECU capacitors? I just want to make sure before I start opening the box.
Thanks,
David
08-28-13, 01:29 PM
#2
could be but the vvti ecu's are newer so its less likely than if you had a 1j non vvti ecu which would be very likely, it is still possible though you never know till you open it up.
are you getting any codes, maybe you coud plug up a odb2 scanner and see if it can talk to the ecu fine but if its intermittent not sure how much that will help unless there are codes stored, then that would help narrow it down.
are you getting any codes, maybe you coud plug up a odb2 scanner and see if it can talk to the ecu fine but if its intermittent not sure how much that will help unless there are codes stored, then that would help narrow it down.
08-28-13, 02:25 PM
#3
Thanks for the reply. Now I am more concerned about boost leak since the symptoms are more like it. I checked all the lines and retightened all the clamps just now and it is still doing the same thing.
It idles and cruise perfectly fine until I apply some throttle then it would run rich (stays 10.0 AFR no matter what).
It idles and cruise perfectly fine until I apply some throttle then it would run rich (stays 10.0 AFR no matter what).
09-03-13, 10:11 AM
#5
I have come to a conclusion that it is a boost leak. I checked all lines from top to bottom and finally found out that the boost controller fittings were loose. I retightened them and it was boosting again. Then the next day, it ran like crap again intermittently. I tried moving the wastegate arm and it moved properly.
I also found a thin coat of oil in my intercooler piping (I heard this is normal). I am 100% sure that my turbo is not blown as I can still boost up to 14psi right now but it hesitates. Plus, it's a CT15B so it's newer than the twins.
I tried putting some thread locker on my boost controller and it didn't solve the problem. It is a hallman boost controller btw. Also I researched that the bleeder hole on the wastegate side of the boost controller might be the problem but Hallman made it that way on purpose to release "trapped" air on the wastegate line.
I am at lost here. Can anyone suggest me where to look next? I am quite sure that my boost controller is the culprit but I have done everything to fix it but no luck.
I also found a thin coat of oil in my intercooler piping (I heard this is normal). I am 100% sure that my turbo is not blown as I can still boost up to 14psi right now but it hesitates. Plus, it's a CT15B so it's newer than the twins.
I tried putting some thread locker on my boost controller and it didn't solve the problem. It is a hallman boost controller btw. Also I researched that the bleeder hole on the wastegate side of the boost controller might be the problem but Hallman made it that way on purpose to release "trapped" air on the wastegate line.
I am at lost here. Can anyone suggest me where to look next? I am quite sure that my boost controller is the culprit but I have done everything to fix it but no luck.
Last edited by jintei; 09-03-13 at 04:22 PM.
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09-03-13, 03:05 PM
#8
I don't think it is your boost controller. It could be a boost leak but I am not sure it would run richer, probably leaner. you aren't getting any codes or do you not have a way to check? almost sounds like your maf connector just got loose or any of the important ones. I would double check the maf on this one.
not sure about the recirculator, but you could take that hose off and see if it is closed or not normally (it should be), and then pull and cap the vacuum line temporarily so it will stay closed as a test.
not sure about the recirculator, but you could take that hose off and see if it is closed or not normally (it should be), and then pull and cap the vacuum line temporarily so it will stay closed as a test.
09-03-13, 04:27 PM
#9
I don't think it is your boost controller. It could be a boost leak but I am not sure it would run richer, probably leaner. you aren't getting any codes or do you not have a way to check? almost sounds like your maf connector just got loose or any of the important ones. I would double check the maf on this one.
not sure about the recirculator, but you could take that hose off and see if it is closed or not normally (it should be), and then pull and cap the vacuum line temporarily so it will stay closed as a test.
not sure about the recirculator, but you could take that hose off and see if it is closed or not normally (it should be), and then pull and cap the vacuum line temporarily so it will stay closed as a test.
I still think that the tiny bleeder hole on the boost controller could be the problem but it's been that way since I bought it. The feeling of driving the car right now is as if the wastegate is opened during part throttle and closed all of a sudden when you apply more throttle. Felt alot like boost spike.
I checked the hose connecting to the wastegate actuator and it's fine. Double triple checked everything...
09-04-13, 02:23 AM
#11
No,its all correct. Wastegate side fitting is the one w the bleeder hole. Opened it up and cleaned the inside and spray a little bit of wd40 and still no luck. Its weird because it was boosting again when tightened the fittings and the next day went bad again. What i dont unserstand is, if i bypassed the bc by connecting the turbo nipple to wastegate actuator it should boost again like stock psi but it didnt. Same boost leak feeling.
09-04-13, 05:11 AM
#12
Try blocking off the stock bov. They're horrible pieces of crap that will do what you're describing. Also, if the vac switching valve for the bov is still in use, get rid of it. Bypass the vsv by running manifold vac directly to the bov.
Oh. Doesn't matter if you're ct15b isn't a ct12, it still sucks! The one that came with my first vvti swap was dead at 88k (kilometers) when it arrived from the importer. The one from my auto soarer swap in my daily right now is making lots of noise after only 3 months use, and 40k kilometers on it before I got it. They just plain suck.
But yeah. Bypass bov vsv, then investigate the bov itself.
Oh. Doesn't matter if you're ct15b isn't a ct12, it still sucks! The one that came with my first vvti swap was dead at 88k (kilometers) when it arrived from the importer. The one from my auto soarer swap in my daily right now is making lots of noise after only 3 months use, and 40k kilometers on it before I got it. They just plain suck.
But yeah. Bypass bov vsv, then investigate the bov itself.
09-05-13, 10:15 AM
#13
So I took off my stock recirculator last night for inspection and it seems to be working just fine:
I even put some copper gasket sealant on the rubber O ring and the gasket and let it sit overnight.
Drove it today to work, still the same thing...
At this point, I can only think of the wastegate actuator / boost solenoid went bad thus making the wastegate hesitates to open / close.
Any other input before I take out the turbo?
I even put some copper gasket sealant on the rubber O ring and the gasket and let it sit overnight.
Drove it today to work, still the same thing...
At this point, I can only think of the wastegate actuator / boost solenoid went bad thus making the wastegate hesitates to open / close.
Any other input before I take out the turbo?
09-05-13, 10:28 AM
#14
I did some research on bad wastegates / bad wastegate actuators and came across this on NASIOC:
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"With the countless threads about boost creep problems with turbobacks on the 2.5l STI, I think this thread should be helpful as a quick summary to those planning on moddifying their STI.
Q) What is boost creep?
A) Boost creep occurs when the wastegate is physically unable to bypass enough exhaust around the turbine on the turbo.
Q) Is boost creep harmful?
A) Yes, boost creep is one of the worst problems you can have with a turbo engine. Boost creep means that there is NO way for the boost pressure to be controlled. Boost pressures in excess of 20psi!!! have been recorded on STIs with TBE before the ECU cuts fuel.
Q) What causes boost creep?
A) Installing a turbo back exhaust whether aftermarket catted or not will in almost all cases cause boost creep to a certain extent.
Q) Are there any other options to prevent boost creep besides porting the wastegate?
A) Yes, Installation of an exhaust that either keeps the stock OEM muffler or one of the stock cats should not cause boost creep.
Q) How do I know if I have boost creep?
A) If you have a full TBE, then you probably have it. A boost gauge will tell you what pressure you are at as well. Fuel cut occurs when the ECU senses boost in excess of 17.5psi for 2-3s. Fuel cut in my experience is a very violent "stutter" from the engine that resembles extreme knock, followed by CEL.
Q) What is the overboost CEL?
A) (P0244) Wastegate malfunction
Q) Is there anything else I can do besides porting the wastegate to prevent the creeping....MBC, EBC, engine management etc?
A) This problem is isolated to the wastegate only. The wastegate is a mechanical system. There are no current workarounds or "fixes" besides this. The 2.5l just flows too much exhaust through the turbo once a turbo back has been added for the wastegate to control boost. If you think of it as a hierarchy, then it should make sense.
level 1) wastegate controls boost pressure
level 2) boost solenoid controls wastegate
level 3) MBC/EBC/ECU controls boost solenoid
Using this logic, if the problem resides on the 1st level, no matter what you do on top of it, you will still have the problem. Whatever (MBC, EBC, UTEC, ECUTEK) is controlling the wastegate CANNOT prevent boost creep if the WASTEGATE is UNABLE TO FLOW ENOUGH EXHAUST to prevent boost creep. A fuel cut defender will not eliminate the boost creep problem, but it will stop the fuel cut. Your boost will still creep up to 20psi, but the ECU won't be able to tell due to the altered signal from the FCD.
Q) My car seems to boost creep when it is cold out. Why is that?
A) Ambient temperature plays a huge role in how well your engine runs. In general, the cooler ambient temperature, the better your engine runs due to the laws of thermodynamics. The colder air causes your engine to make more HP (more work under the curve with lower temps), therefore more energetic exhaust gases, therefore your car is more prone to boost creep when it is cold out. If you live in an area that does not see colder temperatures (AZ for example) too often, then boost creep may never become a problem."
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
This boost creep symptom is the only thing left that is related to the nature of my problem because a couple weeks before this happened, I installed:
- 3" Blitz catback exhaust.
- 3" midpipe with no cat.
- Tomei Expreme turbine outlet (3 inch).
All those mods (probably) increased the chance of boost creep.
Any input will be appreciated, thanks.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
"With the countless threads about boost creep problems with turbobacks on the 2.5l STI, I think this thread should be helpful as a quick summary to those planning on moddifying their STI.
Q) What is boost creep?
A) Boost creep occurs when the wastegate is physically unable to bypass enough exhaust around the turbine on the turbo.
Q) Is boost creep harmful?
A) Yes, boost creep is one of the worst problems you can have with a turbo engine. Boost creep means that there is NO way for the boost pressure to be controlled. Boost pressures in excess of 20psi!!! have been recorded on STIs with TBE before the ECU cuts fuel.
Q) What causes boost creep?
A) Installing a turbo back exhaust whether aftermarket catted or not will in almost all cases cause boost creep to a certain extent.
Q) Are there any other options to prevent boost creep besides porting the wastegate?
A) Yes, Installation of an exhaust that either keeps the stock OEM muffler or one of the stock cats should not cause boost creep.
Q) How do I know if I have boost creep?
A) If you have a full TBE, then you probably have it. A boost gauge will tell you what pressure you are at as well. Fuel cut occurs when the ECU senses boost in excess of 17.5psi for 2-3s. Fuel cut in my experience is a very violent "stutter" from the engine that resembles extreme knock, followed by CEL.
Q) What is the overboost CEL?
A) (P0244) Wastegate malfunction
Q) Is there anything else I can do besides porting the wastegate to prevent the creeping....MBC, EBC, engine management etc?
A) This problem is isolated to the wastegate only. The wastegate is a mechanical system. There are no current workarounds or "fixes" besides this. The 2.5l just flows too much exhaust through the turbo once a turbo back has been added for the wastegate to control boost. If you think of it as a hierarchy, then it should make sense.
level 1) wastegate controls boost pressure
level 2) boost solenoid controls wastegate
level 3) MBC/EBC/ECU controls boost solenoid
Using this logic, if the problem resides on the 1st level, no matter what you do on top of it, you will still have the problem. Whatever (MBC, EBC, UTEC, ECUTEK) is controlling the wastegate CANNOT prevent boost creep if the WASTEGATE is UNABLE TO FLOW ENOUGH EXHAUST to prevent boost creep. A fuel cut defender will not eliminate the boost creep problem, but it will stop the fuel cut. Your boost will still creep up to 20psi, but the ECU won't be able to tell due to the altered signal from the FCD.
Q) My car seems to boost creep when it is cold out. Why is that?
A) Ambient temperature plays a huge role in how well your engine runs. In general, the cooler ambient temperature, the better your engine runs due to the laws of thermodynamics. The colder air causes your engine to make more HP (more work under the curve with lower temps), therefore more energetic exhaust gases, therefore your car is more prone to boost creep when it is cold out. If you live in an area that does not see colder temperatures (AZ for example) too often, then boost creep may never become a problem."
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
This boost creep symptom is the only thing left that is related to the nature of my problem because a couple weeks before this happened, I installed:
- 3" Blitz catback exhaust.
- 3" midpipe with no cat.
- Tomei Expreme turbine outlet (3 inch).
All those mods (probably) increased the chance of boost creep.
Any input will be appreciated, thanks.