Cam install done...car shoots to redline on startup....
Started up car.. shoots to redline.
What can cause this? Just got done with a cam install and such... and we started the car and it immeditately shoots to around 3800... and surges around 3800 bad. Then after 3-4 seconds it will fall to about 500.. idle for just a second.. then die.

If it was a vacuum leak it would mantain the high revs? Instead of falling off and then dying would it not? If you touch the throttle at all while its hanging around 500 it will try and shoot back up to around 3800.

Car is a 2000 LS1
Mods are FM14 cam.. dual springs... Ls6 intake.....

Any help soon ASAP pls.

Aside from a huge vacuum leak.. what else could cause this?

Here is a video of when we were starting it up. At the end when it is revving and surging that is the car doing it.. not us.. we just had to cut it off.

http://s93322652.onlinehome.us/problem.wmv

 

isn't it fairly comon for the car to run REALLY rough on inital start up?

it has to relearn alot of stuff. could the cam sensor be off? that takes a few minutes to relearn doesn't it?

 

I don't see why it would make the car IMMEDIATELY shoot up to 3800 or so on statup.. every cam I have ever seen installed has not done this.

The car was down for alot of months.. and was mail order tuned by Alan @ futral motorsports....

 

the idle air controller won't adjust far enough for the RPM's to shoot to redline, right?

so you have a huge vacuum leak, or your throttle body is stuck open?

 

It'd doesn't go to redline.. I was just meaning it seems to shoot up as if it was under full throttle... it stops climbing in rpms once its get to around 3800 or so.... then it will level off like in the video.. and then fall to 500 or so.. then die. SOmetimes it just hangs at 3800 and then surges like in the second part of the video.

 

Maybe the tune. I know you never get it right on the first shot. But still doesn't explain why it is happening. You have another computer to try on it, would rule the tune out.

 

Only reason I am ruling the tune out is because Alan @ Futral MS did it.. he is one of the best tuners in the country and I have NEVER heard of him messing up before.. if we can't figure it out he is definetely getting a call tho.

 

unplug the idle air controller, that way the computer cannot control it.

then start the car ... i'd bet that would rule out a computer problem.

 

Good chance there's a vacuum leak here. I've taken my booster hose off prior to starting the engine cold before and it has the same characteristics. If I don't catch it before the idle drops it wants to die.

 

Will it rev allt he way to 3800 tho? and then fall?

 

Mine did the same thing shot up to around 3 grand fwhen i 1st started it and idled there for a good 3 min. Than i shut it off and re started it and it was fine right at 900 rpm

 

WAs this right after a cam install?

 

Hey, I would triple check every sensor and plug you even touched during the install. I am betting the TPS is unplugged. Also in case you didn't reset the computer I would do that. If you have a scanner hook it up and try to keep it running. Your prolly just overlooking something small You'll get it done 'cause your a GA boy. later....

 

http://www.cartalk.com/content/colum...anuary/08.html

Found this doing a search.. my coolant temperature sensor broke when we removed the heads.. is it possible since its messed up it would cause a high idle?

 

I think you just found the problem.