misfire...again

[frusciante fan]

a couple weeks ago i was getting a random misfire, ('98 3.8) and the code showed misfires in cyls 1, 2, and 3. i had the fuel filter replaced and some injector cleaner added to the fuel tank. ran it for about 80 miles without improvement. so i took it in again. this time i told them to clean the injectors themselves. they did, and the misfire was gone. i had this done on a wednesday and the next night i took a little road trip of about 110 miles and she ran good, even got 26mpg. i drove it again on saturday to work for a roundtrip of 45 miles. i wasn't getting the greatest of milage but i didn't think too much of it. when i got home saturday night i listened to the exhaust. sure enough i could hear the slight "puffing" sound back again. i drove about 2 miles the next day to fill up with gas and the SES came back on. so here i sit. car's going back into the shop tomorrow...hopefully they can actually figure out what's wrong instead of wasting my money! it's so frustrating because i just bought this piece of junk. the warranty didn't cover the injector cleaning either because it was "regular maintance." but if anything has to be replaced it's covered. it's a long shot but does anybody have a clue what's wrong:

-new plugs, wires, fuel filter
-SES light comes on after a few minutes of idle
-rough start/idle
-cars shifts/drives fine other than at idle

[BobbyZ72]

I had a 99 with this same basic problem, i ended up selling it because of it. i now have a 97"knock on wood" i have not had any problems with i could not take care of. Any ways I turns out the problem with the 99 was the injecter wires, when they come off the injector they are ran back behind the engine where they rub. the rub mark can be a hair line, or something you cant even see. Whats happening is the wire does not always stay in that exact same place, with vibration, heating up, cooling down, the wire moves slighty. This is way it does not do it all the time. Next time this happens reach behind the engine and GENTLY move the wires around. What your going to end up having to do is take the injectors that are causing trubble out, wrap the wires with eletrical tape, put them into their own flexable wire conduit and reinstall them. It helps if you can have a lift so you can get under the car better to see how the wires are ran. hope this helps

[BobbyZ72]

thats why when they cleaned the injectors it ran fine for a while. THEY MOVED ALL THE WIRES AROUND. ;) hint hint.

[frusciante fan]

i had to have my mom drop the car off the morning because i'm sick today. just got off the phone with her and she said that the guy told her the missing (1&3 for sure and possibly 2) injectors need to be replaced. at least the labor and parts are covered for this. they're going to have the whole job done today too, which is suprising. but because there's a Car Quest 80 ft from the dealership, that may have something to do with it.

*crosses fingers*

[BLLDOGG]

hmmmm.....3 cylinders missing and the only problem is bad gas mileage and some puffing from the exhaust. sounda fishy to me unless i missed something. that thing should be rocky like a bronco if half of your engine was down

[frusciante fan]

well i guess all they did was check the codes and add some more cleaner. the mechanic said it was the injectors and to run it some more. i forgot what the name of it was, but it was GM cleaner. so i ran her for a 65 mile trip tonight. the SES was not on when i picked the car up so i wasn't as worried. and i got to a back and turned her loose for the first time. i hit 117 when i ran out of room. the SES didn't come on all night and she ran smooth. from what i could hear when i got back, no misifre. *knock on wood*
for later i bought a couple bottles of Prestone Winter Fuel Injecter with some cold start crap, along with a bottle of Heet that i added just now. cold starts seem kind of rough, but maybe it's just me. or maybe it's because it's been -2 for the morning low lately. i was also told to try a different brand of gas and that temporarily switching to premium would be a good idea.

[BobbyZ72]

Well i hope that was all it was, just dont forget what i told you so if it does it again you can let the mechanic know what he sould be looking for. Switching to premuim is not going to help anything, our cars are computer controled and have no need for premium. You will not notice any diffrence, if you do its all in your head. As for -2 :eek: ,,,,,holy crap!!! Ill just say here in south texas.