5.3 racer

iTrader: (8)

Need help with tuning out a quirk, lol. When the engine is cold and put into gear the idle rpm rises 300-400 rpm then drops back down to normal once "fully" into gear. Example: When started the engine idles at approximately 900rpm when I move the shifter to drive or reverse it rises to 1200-1300rpm then drops back down to 900rpm. This only happens when engine is cold. When warm it is fine. This is a 2002 pcm that pcmforless originally tuned. If anyone has a clue where to start I'd appreciate it. Thanks.

KySilverado

iTrader: (7)

I would suspect the table targert idle speed vs. engine coolant temp (Drive -Park -AC on - AC-off) table is the culprit.

1SlowHoe

iTrader: (28)

Yeah, what he said. Why idle so high? Aren't most running at 600? I was at 500 but had issues with my A/C cpmressor so I bumped it up. Just wondering why you went to 900.

5.3 racer

iTrader: (8)

idle so high? "hot cam" . idle is 900 cold(40*coolant temp). idle is 700 when coolant is warm(160*). my target idle vs. coolant temp table is even across the board. example: 900 rpm at 60 degrees coolant in park, in gear, park a/c on, in gear a/c on. it ramps down to 700 rpm at around 160*. my truck idles great in park, it idles great in gear, it is the transition from park to reverse(or drive) that's the problem. it's only for a second that the idle rises.

1SlowHoe

iTrader: (28)

ok, I'm retarded. I didn't see the cam in your sig. I thought you were running 900 rpm all the time with no cam. That's why I asked why so high. If your tables are correct then I don't understand your rpm jump. Vaccumm issues maybe?

LBSBLOWN

iTrader: (1)

Try looking at the IDLE SPARK ADVANCE tables Idle in Drive & Idle in Park/Neutral and bring them closer together and that should solve your problem.

5.3 racer

iTrader: (8)

thanks! i'll check them this weekend and post results.

5.3 racer

iTrader: (8)

sent you a pm....

02sierraz71_5.3

iTrader: (2)

idle airflow-reduce the base airflow table and the iac back to stock if its been messed with.