weeble1

iTrader: (6)

I just tried firing up my car after it sat for 3 weeks. First start up after TSP 1 7/8 LT, ory, and Ported fast 92 matched to a 95 mil TB. I also deleted the AIR/EGR systems. Still using stock MAF. When I started the car up it Idles around 2000-2200 rpm. It hovers there for a few seconds and it then it will drop down to about 1200 very slowly and will not go below that. When I rev it has great throttle response but it takes FOREVER to down rev. I unplugged the TPS and turned the key to on for about 15 seconds, turned it off and plugged the sensor back in. No change. Any suggestions? Would a leak in the PCV system cause this? I replaced the PCV valve. I removed the LS1 coolant crossover and changed the valley cover bolts so I think the intake is sitting properly. I'm also running the car open Y right now... I don't see that causing an issue but I could be wrong. Any input is appreciated.

Josh

LilJayV10

iTrader: (39)

Try and driving it. The PCM will have to relearn the idle. If that doesn't take care of it take some brake clean or carb cleaner and spray around the intake and T/B and check for vacuum leaks. How are you sealing the bigger T/B to the intake?

weeble1

iTrader: (6)

OK, I'll need to get the exhaust finished up tomorrow morning to drive it. The TB is sealed with the gasket that came with it. Seals up nicely. I'll spray some TB cleaner on it tomorrow also. Thanks for the quick reply.

zacht

iTrader: (18)

hm. first check for leaks and such. do you have tuning software? i kind of had this problem. the iac motor wanted to stay wide open. i adjusted the throttle cracker tables and idle decay rate.

AINT SKEERED

iTrader: (2)

Check your throttle body voltage and make sure it's not opened more the .5 volts.

thunderstruck507

iTrader: (18)

Does the TB have a set screw?

Sounds like it's getting way too much air and the IAC bottoms out trying to fix it.

weeble1

iTrader: (6)

Thunderstruck thanks a lot! I didn't even notice it sitting in there. That solved the high idle but it still takes a while to drop back down. I need to pull the intake back off anyway to fix the coolant crossover that's leaking so ill check the gaskets to see if I pinched one or something.

thunderstruck507

iTrader: (18)

I'm currently in the middle of idle tuning battles with my car.

The screw has to be set and then the car has to be tuned for airflow. If it's still hanging it could be a vacuum leak that is being corrected for or it could still be the tune just not letting it drop soon enough for the conditions.

weeble1

iTrader: (6)

I know that my car had gotten tuned with a cat back, lid, and stall. But I added the lts, ory, and ported fast with the 95 mil tb. Never had any issues with the rpm's hanging before... im leaning towards a vacuum leak. I guess I should still tune it though. I would imagine its pretty lean due to all of the extra air being introduced.

thunderstruck507

iTrader: (18)

You will likely pick up as much power tuning for the longtubes as you did installing them. I would highly recommend at least a mail order tune from Frost.

He tuned a friends car with similar mods and it was spot on.

weeble1

iTrader: (6)

Yea that's the route ill probably go for a temporary fix. Once the heads and cam are on ill probably have it dyno tuned.

weeble1

iTrader: (6)

Ok so it really only does it when its warm... started it today and it did great until it warmed up. Then the slow down rev started.