Driveability Issue Driving Us Crazy
04-04-2009, 03:07 PM
#1
Driveability Issue Driving Us Crazy A friend recently pulled his torque converter out and had it restalled. Since reinstalling it, the car softly jerks as the rpms settle down to idle speed during braking.
If you let the car roll forward at idle, it has the same jerking. When you rev the motor against the brake in drive or reverse, as the revs come down to idle, you can feel it, even though the car's not moving. In neutral, the revs come down smoothly.
No DTC's. We've scanned and even done some tuning, bumping up low rpm spark, editing misfire tables, etc., changed the plugs, cleaned the MAF, inspected all the relevant electronics and hard parts, and have found nothing, and there has been no change to the behavior.
Tuning wise, the only thing left to do that I can think of is some airflow, RAFIG, throttle cracker, etc.
The thing is, before the converter was R&R'ed, this behavior did not exist. That was the only thing done to the car. Now this problem and we can't seem to solve it. Could it be internal to the TC? Any ideas? We're stumped.
If you let the car roll forward at idle, it has the same jerking. When you rev the motor against the brake in drive or reverse, as the revs come down to idle, you can feel it, even though the car's not moving. In neutral, the revs come down smoothly.
No DTC's. We've scanned and even done some tuning, bumping up low rpm spark, editing misfire tables, etc., changed the plugs, cleaned the MAF, inspected all the relevant electronics and hard parts, and have found nothing, and there has been no change to the behavior.
Tuning wise, the only thing left to do that I can think of is some airflow, RAFIG, throttle cracker, etc.
The thing is, before the converter was R&R'ed, this behavior did not exist. That was the only thing done to the car. Now this problem and we can't seem to solve it. Could it be internal to the TC? Any ideas? We're stumped.
04-18-2009, 11:46 AM
#2
I suppose if you went from a loose to a tight converter you will have to do some IAC tuning to stop the car from surging.
When cars are pushing against a tight converter, I sometimes have better luck cutting the timing at the surging point rather then goofing with the IAC tune.
When cars are pushing against a tight converter, I sometimes have better luck cutting the timing at the surging point rather then goofing with the IAC tune.
