OK here's the deal. I have a 96 Camaro with the 3.8L. had 3 things mess up at once. intake gasket (replaced that), bad EGR valve (just replaced that) and then i was in bad need of a tuneup and got that done. I haven't even put 120 miles on the new spark plugs. I've been driving the truck till i could get the valve. Anyway i noticed on the way home that two cylinders were missing when i accelerated. managed to make it the 30 miles on the interstate without any major incident and then when I got off the interstate and started accelerating from the stoplight it didn't miss. It did slightly but nothing hard at all. I just can't think of what might cause that. pugs are brand spanking new as are the wires. and the car ran fine when i drove to class after putting the new EGR valve on. purred like a kitten the whole way had no problem. I've had problems with the 5 and 6 cylinders in the past though. I just don't know what it could be. and based on the way it felt for that period of time compared to how it felt before i made the repairs i would be willing to bet money that it's those same two cylinders. So what all could it be? maybe it still had something to work out and it'll run fine tomorrow who knows but i still would like to know why it's doing that. and btw no check engine light came on either at any point.

 

Find out for sure what two cyclinders it is. The reason for that is that if you have a bad coil you will lose cyclinders in pairs as each coil controls two cyclinders. I believe 3 and 6 are paired on one coil, 2 and 5 on another and 1 and 4 on the third. so if its one of these pairs you can almost be certain that its a coil..... if not there could be a good chance that its your ignition control module.

 

You definitely need to find out what cylinders are acting up. As noted above, if the cylinders in question are related to the coil pack, then swap coil packs and see if the problem follows. Also, dirty/clogged fuel injectors will cause misfire symptoms as well. Also, bad plugs and wires. Seeing that you just replaced the plugs though, I probably wouldn't worry about that.

 

I wish i had one of those code scanners because i don't have the time or the money to take it into a shop and have them hook it up. that's 50 or more bucks just to hook it up to the computer here and I'm a college student taking 19 hours and working. the ignition coil theory makes sense although it feels like the two cylinders that miss are one right after the other which would theoretically burn that argument. I will attempt to find out what cylinders are missing as soon as i can. and maybe it will behave on the way to class i'll post from there if it did or not

 

I think the best thing you could do for yourself right now would be to go to walmart or an auto parts store and pick up a cheap code pulling device. I snagged one at walmart once for around 50 bucks. Then you can find out what cylinders it is for sure (plus Im sure you'll need it again sometime). Going by how it sounds or feels won't tell you much. I had a ton of misfire issues with my V-6 bird a few years ago. It was mostly plug wires. I finally paid a friend to install AC delco wires as they are factory length and he also made sure they werent touching anything, preventing burning and arcing. That fixed my problems since. Moving the coil packs around is a better place to start but honestly I bet you'll find it to be plug wires eventually. Be patient with it and let us know what you find.

And if you cant afford a scanner then autozone and advance autoparts will usually pull codes for you for free.

 

when i changed my plugs i changed my wires as well. and they are spaced pretty well. got those little deals to keep the space on them. I'll see if i can't get my hands on a scanner. she did alright on the drive to class. still missed some but nothing like last night. I'll keep updated as i find out more.

 

I know those cheaper Actron scanners from Wal-Mart, Sear, Autozone ect. can detect misfire codes assuming your are getting an SES light and that is the specific fault. It might not be a bad investment as you might need it down the road on this car or another. I bought one a couple years ago and it has more the payed for itself.

 

Ok I went by Autozone and borrowed their scanner long enough to get the codes. The two I got were P0172 (system too rich, left bank on system 4 sensors) and P0305 (cylinder 5 misfire detected). fuel injector maybe? and if it is then maybe that's causing the misfire? This could be a good case study for the local tech school lol

 

With the P0172 code, I would really begin to suspect an issue with a fuel injector. If you pulled the rail and swapped injectors with another bank and the problem followed, then you will have your answer.

 

How would you go about doing that? is that very hard to do? I'd like to avoid the shop if at all possible cause like i said i'm a full time college student and don't have the time or money for a shop to do it.

 

Not sure how the anatomy is on the V6, haven't dealt with one for some time. The rail is held down by a several bolts and the injectors themselves held in by some sort of retaining clip. You just want to make sure that when you reinstall the rail, that all the o-rings on the injectors have some lubricant on them. You don't want to force the rail back into the manifold with dry injectors, otherwise you risk tearing them.

 

Yeah i see what you're talking back but i think that's more than i can do here at mom's w/out help and some equipment. I'm gonna call the tech school here and see if they can help me out. I've heard that if you can get in touch with the right people they'll do that to give their students some more experience. And of course they're supervised well so it's not like they're gonna really mess it up without the instructors catching it. I would have to agree with your assessment though about the fuel injectors. of course with what a regular shop would charge you could almost get a new engine. certainly a V6 and you'd be well on your way to getting a V8 conversion with the money they charge around here.

 

I had the P0172 code about two years ago... it ended up being my injectors... I bought a set of performance Accel injectors from summit racing as they are cheaper than stock ones from auto zone. If your car has over 100,000 miles then that is the most likly cause. According to the Factory manual it could also be a MAF sensor causing that code... but unlikly. Fix that first and it may make your cylinder 5 misfire go away. If not then we can tackle that problem later. The fuel rail does not require any special tools or equipment except for a fuel line remover as the new GM fuel lines connecting to the fuel rail are held in by a special clip.... you can buy this from autozone for $5. Anyways I did mine myself and at firat it looks really hard but it really isn't. You just have to get a few things out of the way and once everything is free and clear and nothing except the injectors connected to the fuel rail... just take a screw driver and pry up on the fuel rail gently at each injector and puonce all 6 are free... pull it up and over the intake plenium. Now take each injector off the rail and install new ones.... put a little motor oil on each injectors o-ring to allow them to go back in easy.

One question.... when you had the misfire did you get a steady service engine soon light or did it blink at you.... if it blinked at you that means shut it off immediatly.... I drove mine for a few miles and 6 moths later the Catalyic converter burnt out and would not pass emmisions... reason is the unburnt fuel in cylinder 5 goes into the exhaust where it can burn and increase temps in the cat causing it to burn out. You might need a new Cat eventually

 

it was steady. I am one of the smart ones that does immediately turn it off when it blinks. But it was steady and yes it has 132,000 miles on it. I'll look into getting those Accel injectors. maybe that'll help me get more gas mileage than i did before things started going wrong (i was getting between 32 and 35 on average before i started having troubles). I'll get me a set as soon as i get paid and put them on. that's definitely alot cheaper than the stock ones at autozone. Which particular ones would you recommend? i see they have 3 varieties. 202cc/min, 222cc/min, 255cc/min. which one is best? thanks for all the input. I'll deal with the cat when it quits. i don't have to deal with emissions testing yet; not till i move to TN at least

 

Unless you are planning on adding a bunch of mods to make high horsepower such as a cam or nitrous I would reccommend the 19 lbs per hour (202cc/min) as these are stock especially if you are looking for good gas milage....I have the same ones..... works great!