Idle speed too high until car is FULLY stopped?
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Originally Posted by C5Corvette
Anyone know which parameter nails this pest down?
I'm running a 242/242 Comp Cam and the idle and drivability are near to stock EXCEPT...when fully warm the idle will stay at 1400 RPM until the MPH is zero and then it falls ls to 950..
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I'm running a 242/242 Comp Cam and the idle and drivability are near to stock EXCEPT...when fully warm the idle will stay at 1400 RPM until the MPH is zero and then it falls ls to 950..
_______
If all your other running qualities are good and this only happens after the car warms then it's most likely the RAF tables at higher temps that need to be lowered. As you drive track the running RPMs by temp. I like to switch the DIC to metric. The tables are metric. At some temp you will notice the RPMs hanging. Lower the RAF values from that temp and up. In your case I would start with -.50. You will have to be patient and repeat this as the engine temps will have to cool down to do it again. You may have to do it at each temp level and also will have to lower the values by progressively smaller amounts. At some point if you find that .01 or -.01 is too much change then leave a little(100rmp or so) RMP hang in and raise the values in the Throttle Cracker Decay tables from 4mph up.
Too high RAF values do create idle hang, but also cover over other tuning issues that might now appear and some other tables might need adjusting.
For future tuning: I've found that if you work on the VE tables and get them right then the only Idle and Limiter tables that need adjusting are the IAC and RAF tables.