1990 Corvette

[Montobeen]

Hi,
Took my 1990 Corvette out of storage last week and when I started it up it was idling around 2500 rpm's and now it is up almost to 3000 rpm's when idling. When hit the gas the tach jumps up to alomost 6000 rpm's. Anyone know what could cause this? Thanks.

 

[WhalePirot]

I suggest a close, careful visual inspection of vacuum lines and electrical connectors for anything disconnected or cracked, while the car is not running. See if the throttle returns after you move it.

A lesson from my past is to look carefully at any area that was recently touched by anyone, even if it seems unrelated.

 

[vetteoz]

it was idling around 2500 rpm's and now it is up almost to 3000 rpm's when idling. When hit the gas the tach jumps up to alomost 6000 rpm's.
Anyone know what could cause this? .

BUT was the engine ACTUALLY idling at that speed
or was that the revs being indicated on the tacho?????

'90 Vette's have well known problems with the Tacho reading wrong/ erratic / high

 

[G Winter]

BUT was the engine ACTUALLY idling at that speed
or was that the revs being indicated on the tacho?????

'90 Vette's have well known problems with the Tacho reading wrong/ erratic / high

YEP YEP YEP . The tac in my 90 just gives you and idea of what the engine is doing. Sort of a base from what it was before. Mine reads a percentage high. I have read how it can be fixed but not sure it is worth the effort because I seldom use the tac for shift points. I have a feel for the pull and an ear for the engine . I just know when it is time to shift.Sometimes it would be nice to know how far I am pushing it but then the L98 just about can't over wind in it's stock configuration

What I am saying , don't have to much faith in the tac , does it really sound like it is wound up that far? if so that would take a large vacuum leak.
I did have another GM car that actually did idle that fast.After working with it for awile I attributed it to either bad grounds or a bad ECM .The car was such a piece of crap I just hauled it out for junk.

Glenn