I have an erratic idle when I first start my car that goes away as soon as the ecm goes into closed loop. The motor will rev to 1250 and then almost stall and repeat this until closed loop. My car is heavily modded (see sig) and I was wondering if the chip that I have is just calibrated too rich. On a scan tool the block learn levels out to the 118 - 120 range at idle. So I guess my question is will an overly rich fuel map make a engine idle this way?? I have already checked for vacuum leaks and I have not found any. By the way the car is MAF equipped (1989 so no cold start injector)

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355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), Mufflex 4' cat back, B&M shift Kit, 2500 converter, and 3.27s.

 

[QUOTE]Originally posted by mike89z:
[B]I have an erratic idle when I first start my car that goes away as soon as the ecm goes into closed loop. The motor will rev to 1250 and then almost stall and repeat this until closed loop. My car is heavily modded (see sig) and I was wondering if the chip that I have is just calibrated too rich. On a scan tool the block learn levels out to the 118 - 120 range at idle. So I guess my question is will an overly rich fuel map make a engine idle this way?? I have already checked for vacuum leaks and I have not found any. By the way the car is MAF equipped (1989 so no cold start injector)

Are you running a stock chi with that, or are you editing your own?.
If editing your own, just need to lean out the cold O/L AFRs

 

Grumpy, I am running a Fastchip that was custom burned for my combo. I did try the stock chip but it did the same thing, which makes sense to me because it is meant to be used with 22# injectors, not 24#. I dont know how much you know about prom tuning but I am fairly new to it. On a MAF system should I change the mass airflow table to lean out the mixture. There are no tables listed for cold air/fuel ratios that are not linked with load or temp. What do you think I should alter? I am using Tunercat by the way.

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355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), Mufflex 4' cat back, B&M shift Kit, 2500 converter, and 3.27s.