My car has Vt stage 2 cams and some bolt ons. Since I have had them in and tuned my car stalls out a lot when i put it in neutral. If im driving and put my car in neutral the rpms freefall down to around 200, sometimes the car catches it and the rpms shoot back up to 1000 and stabalizes while other times the car stalls out. This makes it very difficult to drive and not very enjoyable. I thought it was a tune problem but he has had it twice since then and says everything is fine with the tune. The wierd thing is that it only seems to do this until it is heated up. Once it is heated up it performs normally. Any ideas what my problem could be?

 

You know, I had a similar problem except my car would stutter and if I idled right before or after it would happen, my rpms would drop low and then pick back up, or just stall out. And just like you, it only happened until the car warmed up. New plugs fixed it for me so maybe try that?

 

hmm the plugs are pretty almost brand new but ill check them out thanks for the heads up. Maybe they aren't gapped correctly or something

 

I'd also clean the Idle Air Control valve

 

being it's temp related, open loop vs closed loop issue, I'd say O2's sensor(s) or maybe even an IAT or ECT sensor problem.....

 

Thanks randy,
So far i've heard IAC needs cleaned
Change Plugs possibly
Tune problem
small vacuum leaks(a few ppl said these are very very sensitive with larger cams)
O2 sensors
IAT
ECT
Cams need to be degreed

 

I got the same exact issue with the xe270 cams. It still happens when I have the AC or heater on sometimes, just as I come to a stop (I let out on the clutch a bit and spin the motor back up and it usually catches on). Before I adjusted the tune it'd do it all the damned time. I adjusted the tune with 10% more fuel from 0-500 MAF counts and that pretty well takes care of it. It's still kinda a pig till it warms up though. There's fuel suspension issues with the reduced vacuum signal from big cams. You may also try advancing the timing just a hair during warmup. My wrench tells me that big cams like a little more timing to idle nice.

 

ya its wierd because if i start my car it idles fine, its not till i drive and come to a stop that the rpms fall fast down to around 200 sometims shoot back up and catch and somethimes shoot back up and then freefall again and stall