GDP

For the past few months my 'vette has had a slightly rough idle, which I just attributed to a fuel filter that needs to be replaced. 32,004 miles without a fuel filter change. Anyway, the rough idle seems to be gone, or nearly gone, from about 150*-170* F oil temp. After that it seems to run normally, with only the slightest rough idle.

This morning was different. When I first started it up, it took a few clicks to get the engine going. It usually starts right up. The oil temp was 46* F when it started up. At around 58* F the idle was fairly rough, but it was pretty cold out today so I just figured it was that. Well I got it to about 130* F before I got to the restaraunt for breakfast. Came outside and started it up, and it took about eight or nine clicks to get the engine to fire. Odd, that has never happened. Well after the engine started up, it was on for about 1 second before it almost shut itself off, but at the last second fired back up again and all was fine. When I started it up it was at 147* F. The idle was very rough, and the whole car was shaking. WTF? :confused: The rough idle continued until about 168* F.

With 32,004 miles I know the fuel filter should be replaced, could it alone cause this stuff? Could any of this be attributed to the cats, fuel pump, O2 sensors, plugs, wires, ignition, or coil? I know that even with the oil temp at 58* F, the 'vette should not idle that roughly. I'm taking it in to the local Corvette-only mechanic on Friday, but was wondering if any of you know what the problem is so that it doesn't need to be left overnight in order for him to see the problem the next day for himself.

ittlfly

I don't think the oil temps have much to do with the idle problem. I'd take a look at the Idle air control (IAC) located on the throttle body. It may just be dirty or the pintle is stuck. May need a good cleaning. Just a thought.

Nathan Plemons

Can't be anything serious. I doubt it's your fuel filter really though, that shouldn't be temp related. I'm gonna have to say that it's something to do with some sensor not acting right. Almost sounds like it's not getting accurate information about the temps you have and thus when it warms up it runs a little better. I'm not sure what but I'm gonna guess either something with the IAC or just a faulty sensor somehwere.

Good luck! :cheers:

GDP

I know it's not something serious, it's just that this Corvette mechanic charges an arm and a leg for everything. For instance, "AROUND" $160.00 labor for muffler elims, just labor.

I just went and checked all of the sensors on the throttle body and intake. They all seem clean as a whistle.

I'm not implying that it's temperature related, the rough idle happens to coinside with the oil temps. :cheers:

tbwstingray

HI, MY DADS 35TH HAD A IDLE PROMBLEM SIMILAR TO YOURS. WE REPLACED THE ''IAC'' SENSOR AT THE BASE OF THROTTLE BODY, IN FRONT, THAT SOLVED HIS PROBLEM. :iagree: :smash: :smash: THIS WAS ON A L98 NOT SURE ABOUT THE LT1, GOOD LUCK :flag :seeya


[Modified by tbwstingray, 2:56 AM 12/11/2002]

GDP

TTT

Sandy S

Did you just get gas somewhere? I got a bad tank-full one time and my car was really sick. Perhaps put some dry gas additive in the tank. Plugs could make it rough and hard to start it but the miles seem too low.

I had one plug wire come off (I didn't push in on far enought) and the car would shake.

xlr8nflorida

Last time my car acted like yours, It was the Opti-Spark crying out that it is a piece of poopie and it needed to be replaced ASAP.....

I hope yours is a cheaper fix... :yesnod:

sunrise.cm

Would guess optispark or fuel requlator if you have checked all sensors. Good luck :seeya

vetteweiser

Mines been doing the same thing. I havent paid attention to the oil temps, or any other temps.

What its been doing is at start up, in the morning (outside temps in the mid 60's) is 1. it'll fire right up, or take about 2 seconds (maybe 3 turnovers), idle high, then drop low. It has stalled out. I know its going to act funny when the ASR SERVICE light stays on. When the engine is about to stall out, the check engine light will come on. If i save it, the check engine light goes off. I can then shut the car off, turn it back on and everything is fine :crazy:

This is on a 93, LT1, only mods are LT-4 roller rockers. Total miles on the Vette is 125K. The opti has been replaced recently (within 3 years, or 3,000 miles if I'm not mistaken). I guess it could be the opti, but I'm not sure. I think this started to act this way after I exercised it one night :D (did a high speed run... lasted as long as it takes to get to 120mph)

Think its the same problem as yours? or do I have something totally different? (btw, didnt mean to jack your thread with my own problem :cheers: )