4U2BNVS

iTrader: (2)

I don't know if this is the right spot for this so i will just start it here.

I have a 1999 Z28 with a 6 speed an MS4 cam and LS6 heads. The problem I'm having is it has been tuned for over a year now, but if i drive for awhile at 65 mph, when i slow down to come into town which is only 40 mph i just pull my shifter into neutral, it will all of a sudden rev to the moon on its own.

I'm talking rev to 7000 without me touching the gas. Then only way to make it quit is put it back in gear or slam on the brakes about 3 times.

Does anyone have a clue what the hell this could be. Is it a vacuum problem or something?

I appreciate anyones help ahead of time.

Thanks James

4U2BNVS

iTrader: (2)

to the top.

This might need to be moved

SOMbitch

iTrader: (8)

I would have your tune looked at.......

King Nothing

iTrader: (9)

have the tune looked at or check for vacuum leaks . . . i had a nasty one and it was like i had cruise control from 10MPH that would take me up to 45mph on it's on lol i'm an auto

SOMbitch

iTrader: (8)

If the idle comes down when you come to a complete stop I think it is your tune...... If it continues to high idle when stopped it is prolly a vacuum leak.

Jon@Texas-Speed

iTrader: (18)

I would check for vacuum leaks first. If not, that should be able to be tuned out of the car. Has it been doing that since it has been tuned or did it just start?

Jon

4U2BNVS

iTrader: (2)

It did this before i got it tuned, when i just had your mail order tune Jon, but i believe it was a vacuum leak. I had it tuned and it was fine for a year and now its back to doing that or when i back up it wants to stall and it didn't do that before. I wish i had an easy way to check for vacuum leaks.
Actually couldn't i use some soapy water in a bottle and spray around my hoses?

Marc 85Z28

iTrader: (8)

The only way a vacuum leak could cause your engine to rev to 7000rpm would be if it was a very large leak and your tune is causing the engine to run very rich.

Soapy water won't help. This isn't like a leak in a tire. The intake will have less than atmospheric pressure, so it will suck in anything you spray (no soap bubbles). Spray carb cleaner instead and listen for change in engine tone and idle speed. Or you could just remove and inspect the PCV system.

You may also want to monitor your TPS while this occurs. It would rule out a throttle blade that doesn't return or a faulty TCS/ASR module.

4U2BNVS

iTrader: (2)

My car doesnt have the PCV system so that wouldnt be the problem. I checked with carb cleaner and it doesnt rev so i must not have a leak. I think it is in the tune. Guess its time to get it tuned again