missing at idle

I have a 92 3.1 rs with over 165,000 miles and I'm having a little bit of a prob.....I know with so few miles that may come as a shock but here it is.....she seems to be missing at idle speed, not all the time, only sometimes. I just replaced the plugs and it's still doing it. I took it to firestone and had them do their fuel system maintenance which consisted of running some chemicals through the injectors under pressure or something like that to clean all the carbon out of the fuel system.....anyhow, when I got it back I thought it wasn't doing it because it was idling so damn smoothly but then I drove around for a while and when I got home and parked it, it ran kinda rough for a min and then it died. She started right back up and ran ok but still idled kinda rough. I have checked my timing, and cleaned the egr valve. They told me that they had an o2 code but they cleared it out and it hasn't come back since I have had it back. I concluded that it is only missing at idle and is only doing it when it is warmed up which would account for the way it was running when I picked it up. does anyone have any suggestions as to what I should check next? thanks.

Take out your MAF and clean it with throttlebody cleaner.. Be gentle.. And replace your o2 sensor! Its probably malfuntioning and it wont Always throw a code..

Other than that, If its an actual miss, its probably an Ignition fault.. Check all your plugs again.. Make sure you didnt crack them puttin it.. its common.. Check over your wires, Use die electric grease (spark plug grease) on both ends of the wires when re-installing them.. and check your cap and rotor.. I like to use QuickStart (ether) spray to clean out the cap.. MAKE SURE ITS DRY before you re-install the cap..lol

hey thanks, I'll check all these things and hopefully that will fix it......

my trucks distributer cap is corroded pretty bad, same with the rotor dealy. Would spraying the throttle body cleaner on my trucks stuff make it spark better? It's crazy boggy at start and im positive thats the reason why. No good spark.

ur better off just getting a new cap and rotor, the cap probly has carbon tracing around the inside of it. there not that expensive

Ok cool ill do that. I was just looking for the cheapest way cuz im a sleezy cheap poor dumb slob. :biggrin:

i use to do the same things. i use to take 220 sandpaper and clean the contacts on the inside of the cap just to get another 1000 miles out of it, then i got stranded and had to walk home. so i decided $15 wasn't worth walking :smile:

$15!? omg i went to checker today to get the most genaric spark plug wires, and the cheapest rotor and cap and it was over $110!!! So i dropped it on the counter and walked out. It was $56 for a fucking plastic cap....people are evil nowadays haha. Where else can i find one that isn't made out of plastic from the IV bag surgeons used to save George Bush with when he choked on a damn pretzle or whatever :lol2: I swear...how in the hell can a plastic cap cost $56!?!? HAHA and thanks for the suggestion of cleaning it and all, im ganna do that tonight cuz i cant afford $110 for some plastic lego pieces or some shit. Plastic cap...or a half tank of gas....hmmm hard choice there.... :loser:

geez man, what kinda truck and what year do ya have?

Chevy 89 C1500. The Checker by me is notorious for being pretty sleezy too though.
http://files.automotiveforums.com/gallery/watermark.php?file=/501/215914Nicks_Truck_Body_auto.jpg

Your gettin ripped off!!! I can get an MSD cap for about $19.00CDN!
and a MSD rotor is about $10.00

Thats why i just tossed it on the counter and walked out haha.