Ought1-Z28

A couple of days ago I noticed that when I shifted gears, the engine would jump 100-200rpm's as the clutch was disengaged. Tonight I was driving home, and went to coast down a hill so I pulled it out of 5th and the rpm's immediatly went to 2500 from just over 1100. Curious I experimented, and it will idle high, around 1050-1100rpms with no load on the engine. ( no radio, lights, a\c) when I turn on the lights, radio, and a\c it runs much more extreme into the upper rpms.(3000-4000) It also only seems to do this when the car is in motion, if I am stopped it will idle a little high 1000-1100, when I tap the throttle it will speed up but immediatly return to "idle" range . When I am moving with the car in neutral and I tap the throttle it will idle down very slowly if at all, but it won't come down to where it is supposed to be, untill I come to a stop. One other thing, It doesnt seem to be pulling when it is in gear, I havn't really noticed anything unusual and out of the ordinary while in gear, just when in neutral or when the clutch is disengaged.

My mods are an ASP crank pulley and a TSP lid. I just installed the lid at the beginning of the week.
I know that this post is slightly incoherent, but if you can help me I would really appreciate it.
Shawn

Drew98TA

Could possibly have an air leak. Air getting into to the TB where its not supposed to. Check the seal around the TB, MAF, and lid. Just make sure everything is nice and snug. Hopefully that'll work.

SSN8R

I agree with Drew98TA. Most likely a vacuum leak based on the fact that you made changes to the air intake recently. Some of what you described in your post is normal. My car will not go to the 'normal idle' until the car comes to a stop. I believe the newer cars have a speed sensor the computer uses to keep the RPM at a higher idle while the car is moving.

The only other guess I would have is; it acts a little like the PCM thinks you have an automatic, but you do not list programming as a mod.

Good luck,

DEEZ98Z

iTrader: (5)

I had this happen to me but my car is a 98 so i have the LS1 intake and EGR tube.... the donut (gasket) that goes around the air tube had been sucked into the intake partially. The unwanted air into the intake was making my car rev like that.... Long story short... like said above check for a leak

Ought1-Z28

No programming, and I will check for any leaks. Could it be that the AIR hose is totally unrestricted and siphoning fresh air into the exaust?

DEEZ98Z

iTrader: (5)

What do you mean??? Did you change something and then this started? Oh and I am guessing that you are in the Corps.?

Ought1-Z28

I installed the airlid so the air tube is no longer hooked up to a vaccume source.
I was 0311, got out in 2000 and then went reserves last month.

Steve98Z

Same here, on my 98 I had the same problem.........

DEEZ98Z

iTrader: (5)

I dont know if that is your problem... but if that is all that you changed then I would say that is it... I know there are different lids for different years 01-02 lids are different. Maybe you got the wrong lid and need that hose hooked up?

I am a 2621 (Signals Analyst) and about to get out in May

Ought1-Z28

Well I am an idiot.. I forgot to tighten the bellows clamp on the intake. What a tool... thats something that a four year old wouldn't forget. let the flaming begin...

Ferocity02

iTrader: (60)

I've done that before! I rememberd to tighten it while I was going so I pulled iver and used a dime to tighten the clamp to the TB. The RPM were jumping like you said.