Engine stalls when coming out of boost
#1
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ok so my car idles great, runs like a dream, and the new turbo is working great-
the only remaining bug is this- it occasionally stalls (turns off) when I come out of boost. It's almost as if the computer doesn't realize that the throttle has closed, and so the ISCV doesn't open soon enough. and the engine dies.
I do have a lighter flywheel (about half the weight of stock) is this the problem?
or,
is it the throttle position sensor? is it adjusted wrong?
currently, I have to set the idle at 1.5k rpms or it dies every time I come out of boost. ideas?
Thanks
the only remaining bug is this- it occasionally stalls (turns off) when I come out of boost. It's almost as if the computer doesn't realize that the throttle has closed, and so the ISCV doesn't open soon enough. and the engine dies.
I do have a lighter flywheel (about half the weight of stock) is this the problem?
or,
is it the throttle position sensor? is it adjusted wrong?
currently, I have to set the idle at 1.5k rpms or it dies every time I come out of boost. ideas?
Thanks
#7
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With a Voodoo, the configuration of the idle control system should be unchanged.
I'm thinking this may be nothing more than a stock ECU not liking a super-light flywheel. Its idle algorithm is designed around the assumption of the dynamic properties of an engine with a stock-weight flywheel.
I'm thinking this may be nothing more than a stock ECU not liking a super-light flywheel. Its idle algorithm is designed around the assumption of the dynamic properties of an engine with a stock-weight flywheel.
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With a Voodoo, the configuration of the idle control system should be unchanged.
I'm thinking this may be nothing more than a stock ECU not liking a super-light flywheel. Its idle algorithm is designed around the assumption of the dynamic properties of an engine with a stock-weight flywheel.
I'm thinking this may be nothing more than a stock ECU not liking a super-light flywheel. Its idle algorithm is designed around the assumption of the dynamic properties of an engine with a stock-weight flywheel.
Is the voodoo box "tuned" correctly?
#13
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I very seriously doubt that the Voodoo box has anything at all to do with this, assuming it's installed correctly.
It is possible that the MSD box might be contributing to the problem. I don't know much about how this box works internally (the schematics and code were never published) however I can see two possibilities:
1: If the MAP signal feeding the box has been taken from a point before the throttle, then the box will still be seeing boost after you release the throttle and depress the clutch. In this case, it will still be retarding the ignition, and this will make it harder for the ECU to achieve idle.
2: If the box has a large degree of latency between when MAP actually drops below atmospheric and when the box "releases" from retard mode, it will have the same effect.
It is possible that the MSD box might be contributing to the problem. I don't know much about how this box works internally (the schematics and code were never published) however I can see two possibilities:
1: If the MAP signal feeding the box has been taken from a point before the throttle, then the box will still be seeing boost after you release the throttle and depress the clutch. In this case, it will still be retarding the ignition, and this will make it harder for the ECU to achieve idle.
2: If the box has a large degree of latency between when MAP actually drops below atmospheric and when the box "releases" from retard mode, it will have the same effect.
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You adjust it so it knows when it sees boost. If the wrong light is coming on before boost, it's probably turning off late. It's a long shot, sure, but easy to check, and sounds like it's not the issue.
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I should add: it's possible that the MSD box is malfunctioning, and causing ignition retard all the time, or at times when it should not. If you have a timing gun and a hand-operated vacuum/boost pump, you can test this rather easily.
#17
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where should my base timing be? should it be at 0 or advanced 6 degrees?
I adjusted the throttle position sensor, and it no longer stalls. I'm not sure if that was the correct fix or not.
tonight, i'm going to check the timing again, and make sure the voodoo is still tuned correctly. thx guys
I adjusted the throttle position sensor, and it no longer stalls. I'm not sure if that was the correct fix or not.
tonight, i'm going to check the timing again, and make sure the voodoo is still tuned correctly. thx guys