92 Lesabre, 177k mi, stumbling at idle

[Andreas E.]

I'm back... at least it's been a few months.

About two weeks ago, my 92 Lesabre started stumbling at idle. I've replaced the air filter (was due for that), spark plugs and wires. The spark plugs were normally worn, and not worn out yet. I use NGK's V-power and never had a problem with them. We had a bit of a dry spell last week, and this week it's back to normal wet Pacific NW weather. It seems the stumbling has gotten worse since it started puring again. The check engine light has not come on.

What's next? Coil packs? I read in a different older thread that a weak battery could cause the same problem? The voltage reads fine (13-14V.) However, I do have some aftermarket wiring hooked up to the battery (via self-resetting fuses) for trailer towing. The Haynes manual also suggested checking for vaccuum leaks?

Any help is as always appreciated. I want to get her to 200k and beyond!

[maxwedge]

Hmm, stumbling means a missfire at idle, ok when driving?

[Andreas E.]

Yes, while driving there are no problems. When coming to a stop after driving for a length of time, it also idles fine for about 20-30 seconds before slowly starting into the stumbling again. It feels very much like a misfire, but wouldn't those cause the check engine light to come on?

[maxwedge]

92 had no misfrie codes, disconnect the egr see what happens, also try cleaning the throttle body and idle air control.

[Andreas E.]

I'll try that... it's been a while. Perhaps it's all gummed up again. Thanks!

[Jrs3800]

92 has no EGR...

You need to clean the MAF with some MAF cleaner first... As stated clean the throttle body and IAC passage...

Check the plug wires as well..

[maxwedge]

Hmm, Napa shows one and so does Rock Auto?

[Jrs3800]

Trust me... the Vin L 90-92 was an EGR'less motor... If this is indeed a LeSabre 1992 model it will not have an EGR..

The 88-91 Vin C had an EGR... The 91.5-95 L67 Supercharged had an EGR..

[maxwedge]

Probably right, parts listings can be wrong all the time, obviously someone who has this car can see whether there is one on the engine.

[big white bufflo]

i have a 92 buick there is no egr try maf and iac and a can of injector kleener in the tank i would not think its coil packs

[Andreas E.]

It is a 92 VIN 'L', so no EGR. I did clean the throttle body and there was some improvement, to the point where it's still noticeable but not bothersome.

I was thinking fuel injectors as well. I have not put a can of cleaner in it yet. Since we were below freezing for a week a little while ago, I did put in a bottle of heet.

[Jrs3800]

You might try a bottle of slick50 fuel treatment formula or the like.. $8-$10 and see if that helps...

Have you done the MAF cleaning?