Hmmm......

[Chevelle454]

Well, I know that this isn't exactly the right message board for this, but I did quite a bit of searching and couldn't find a message board for a car like this. Here's the deal:

I have a 1988 Buick LeSabre with the 3.8 Series I engine. It runs perfect, starts right up everytime. The only thing is, when it idles, it idles rough. Any weather, hot, cold, rainy, humid....it doesn't matter.

This car has the delco equipped coil pack system(not the magnavox system). It has a pack for every 2 cylinders. Could one or more of these packs for some reason be misfiring at idle but work fine above idle? How could I check? I don't really want to put in 3 new coil packs if it isn't necessary...

Hopefully someone here has had a GM series I engine and can tell me if there's has idled the same, or if something is wrong with mine. I have been told that the Series I engines have always idled rough, straight from the factory. That doesn't seem like it would be true, but I can't rule it out just yet...

Thanks for any input or suggestions that you guys may have...

-Scott

[stickshift_or_walk]

Could be a vacuum leak. I had very similar problems with a '88 Riviera. Turned out to be a bad PCV valve.

SSOW

[1969 GMC]

My old '89 Lesabre (144k), '89 Olds 88 (130k), and now my current dd '88 Lesabre (89k) never had a funny idle. Lots of electrical problems, but never anything engine related.

[garold99]

This may not help since its a Ford example. But my wifes car is a Ford Crown Vic 90 model. Anyhow it had an oil leak around the valve cover gaskets so we changed that out. But to do that we had to pull the intake manifold, so we changed the gaskets there also.

Anyhow to pull the manifold we had to unplug lots of stuff to get it apart just to change the valve cover gaskets. This is a 5.0 liter engine. One of the things we had to unplug was the ICS (Idle Control Sensor). Well we stuck the connection in under the dash and then when putting it all back together couldnt remember if the ICS had something connected to it or not and couldnt find a connection wire that would run to it.

Before I go any further let me state that my Bro-in-law is the one who did this while I was at the parts store getting gaskets. So I didnt see how he pulled it apart and what went where as far as the connections went.

Anyhow we got the car back together with the exception of the ICS and the car would idle rough and stall out at take offs and when comming to a stop. So I adjusted the idle up, that worked a little bit but after awhile it went back to doing the same thing. I spoke to a friend who knew the engine and he looked at it and asked where the connector was for the ICS. I had no clue.

After a couple days searching I found it stuck up under the dash by the firewall, plugged it in and everything has worked fine since.

I have seen on other message boards (Ford ones) where folks have had the rough idles and they took their ICS off and cleaned the oil out and it worked just fine after that.

So you might check that. On a Chevy they may call it an IAS. Or maybe the Ford calls it an IAS and the Chevy calls it an ICS, I cant remember.

This might not help, but its just an idea.

[Chevelle454]

Thanks for all the help, guys...

It turned out to be a bad PCV valve, which cost me a whopping $1.17 with my discount. I couldn't find the stupid thing at first! It is located towards the center of the intake manifold, not on the valve cover as I would have suspected...

Anyway, it idles nice and smooth now and drives a whole ton better.
Thanks again,
-Scott

[stickshift_or_walk]

YES!!! Finally nailed one! Wouldn't ya know it'd be on a Buick...

Glad it helped....SSOW