HPTuners Injector Pulsewidth Question
Thread Starter
Teching In
Joined: Dec 2005
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HPTuners Injector Pulsewidth Question Guys: I log "Average Injector PW" in HPTuners and it is reporting bank one different than Bank 2 when I am on boost. The exhaust sounds like it is missing and popping a little on boost as well and the power is definitely not what it should be. I suspect a clogged fuel injector or something like that but I would like to know how that "Average Injector PW" value is determined.
Anyone know?
The car is an STS TT 402 Corvette. I am running in 2Bar SD mode so the O2's cannot have anything to do with this. And whatever it is, it was not doing this a couple of weeks ago and it is getting worse. On the 18th Bank 1 = Bank 2 in the log and now Bank 1 = 12.6msec and Bank 2 = 11.4 msec.
Thanks!
Anyone know?
The car is an STS TT 402 Corvette. I am running in 2Bar SD mode so the O2's cannot have anything to do with this. And whatever it is, it was not doing this a couple of weeks ago and it is getting worse. On the 18th Bank 1 = Bank 2 in the log and now Bank 1 = 12.6msec and Bank 2 = 11.4 msec.
Thanks!
FormerVendor
Joined: May 2006
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You might get a quicker response over on HPT's forum. Can't imagine that is much more complicated than some sample of montiored pulsewidth's. The PCM is the source of the commanded pulsewidth. Of course, nothing ever seems that simple in a GM controller, and I wouldn't be the first time I was wrong.
Thread Starter
Teching In
Joined: Dec 2005
Posts: 20
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You might get a quicker response over on HPT's forum. Can't imagine that is much more complicated than some sample of montiored pulsewidth's. The PCM is the source of the commanded pulsewidth. Of course, nothing ever seems that simple in a GM controller, and I wouldn't be the first time I was wrong.
FormerVendor
Joined: May 2006
Posts: 187
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Sounds about right (at least I would hope so): monitor airflow (eithe MAF of SD), derive base fuel need based on that and commanded AFR, add in all compensating factors (STFT, LTFT, Voltage, Temp, etc.)
Definitely try swapping the injectors. Quick and easy way to see if the problem moves with the mechanical device. Good luck.
Definitely try swapping the injectors. Quick and easy way to see if the problem moves with the mechanical device. Good luck.
Guys: I log "Average Injector PW" in HPTuners and it is reporting bank one different than Bank 2 when I am on boost. The exhaust sounds like it is missing and popping a little on boost as well and the power is definitely not what it should be. I suspect a clogged fuel injector or something like that but I would like to know how that "Average Injector PW" value is determined.
Anyone know?
The car is an STS TT 402 Corvette. I am running in 2Bar SD mode so the O2's cannot have anything to do with this. And whatever it is, it was not doing this a couple of weeks ago and it is getting worse. On the 18th Bank 1 = Bank 2 in the log and now Bank 1 = 12.6msec and Bank 2 = 11.4 msec.
Thanks!
Anyone know?
The car is an STS TT 402 Corvette. I am running in 2Bar SD mode so the O2's cannot have anything to do with this. And whatever it is, it was not doing this a couple of weeks ago and it is getting worse. On the 18th Bank 1 = Bank 2 in the log and now Bank 1 = 12.6msec and Bank 2 = 11.4 msec.
Thanks!
SD means no MAF, not no 02s
what are your fuel trims locked at when WOT? Sounds like one is locking in positive and offsetting one bank...
Thread Starter
Teching In
Joined: Dec 2005
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Good point. I have LTFT turned off and Closed Loop turned off and I did not realize the PCM could still add fuel and could also add it to only one bank. I'll go back and look at the fuel trims. Thanks!
So you are OLSD, and unless you never cleared/reset the trims in the scanner, you are right, they should have no influence.
More than one person has been tripped up by not logging LTFTs because they were in OL but had previously positive LTFTs that remain. It's easy to forget, try resetting them in your scanner and see how that does.
More than one person has been tripped up by not logging LTFTs because they were in OL but had previously positive LTFTs that remain. It's easy to forget, try resetting them in your scanner and see how that does.
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Also ensure that you have STFT disabled, as these can still be active in Open Loop. Log your O2 voltages, STFT, LTFT, as well as the Closed Loop/Open Loop status bit to identify this issue. It sounds like a fuel correction issue that the PCM is doing.
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Thread Starter
Teching In
Joined: Dec 2005
Posts: 20
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So you are OLSD, and unless you never cleared/reset the trims in the scanner, you are right, they should have no influence.
More than one person has been tripped up by not logging LTFTs because they were in OL but had previously positive LTFTs that remain. It's easy to forget, try resetting them in your scanner and see how that does.
More than one person has been tripped up by not logging LTFTs because they were in OL but had previously positive LTFTs that remain. It's easy to forget, try resetting them in your scanner and see how that does.
Thread Starter
Teching In
Joined: Dec 2005
Posts: 20
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I plan to swap the injectors bank to bank. Interestingly, my wideband is on Bank 2 and I think the problem may be on Bank 1. If the issue is an injector I will know immediately from the wideband when I swap them.
I guess this means I should have dual wideband O2 sensors!
