I feel sick, the car barely runs now...
 

My son asked me to find him a nice used car while he was finishing up his technical training in the Air Force. He will be an F-22 crew chief at Langley AFB in Virginia in a couple weeks. Well I found him a nicely cared-for black 2001 V6 Camaro with 120K miles, T-tops and a really nice aftermarket sound system. I fixed a couple small items on the car and brought it to the airport for him to drive it home after his nearly 8 months away from home.

The car had been driving perfectly up to then. I did have the evap purge solenoid replaced about a week prior, but that never caused any performance issues. The trip from the airport was about 20 miles. By the time he got off the highway near our house, he said the CEL was flashing. He immediately parked it at the house and I scanned it and found one code - P0302 - cylinder 2 misfire.

It was idling very rough. I spoke with the previous owner (who bought it at 35K miles) and he said this happened once before a couple years ago and it was a coil pack. So I pick up a new one and thought that might fix it. Wrong.

I did a spark test and number 2 wire was sparking quite nicely. I still bought a high quality set of wires and plugs from NAPA and put them on. There was no change. The car barely has enough power to limp up the driveway into the garage and the exhaust smells really bad - like fireworks and eggs. I read a nice write-up on this at OBD II Code P0302 , but thought I would inquire here where all the cars are Camaro V6's.

I will try to find a fuel pressure gauge next to see if I have good pressure at the injectors, but do any of you have some wisdom to share with a dad who is feeling sick about his used car selection for his Airman son who is supposed to drive his new car from Missouri to Virginia very soon?

start with the basics, air fuel spark.

Have you tried swapping injectors/coil packs from one of the cylinders that is working? What does the spark plug look like?

If I'm you, first thing I do is swap injectors and see if your misfire moves to the other cylinder

Miss fire code does not mean the spark did not fire it, it means that when the plug was suppose to fire the engine did not see an increase is speed like it did when the other cylinders fired. So basically anything that could cause a cylinder to fire weakly can cause a miss fire code. I would pull the plug and see if you can see anything going on. Replace that plug just be sure you do not have a internal crack in the plug. I would do a quick compression test while I had the pug out just to be sure.

Fuel pressure test then rotate the injector to another cylinder and see if the miss follows. Looks for vacuum leaks leading to that cylinder, If everything shows good swap in a new spark module.

Or just take it to a good mechanic and he will hook it to a scoop and tell you what is wrong with it.

I did clear the code and tried swapping the 2-5 and the 3-6 coil packs, but the code still came back P0302. I have not swapped injectors yet. The plug on cylinder 2 was noticeably fuel fouled but the spark plug checking tool showed a hot consistent spark on no. 2 wire.

Thanks for the good advise. I will do a compression check too so I can rule out valve/ring concerns. I may have to concede eventually and take it to a shop; but I have been doing all my own diagnostics and repair since before OBD I, so it's a bit of a kick to my pride. And I admit I am a bit frugal too (but NOT cheap).

Ok, I didn't go threw what all was said, but I was having this same problem happen to me on and off. After taking it to several shops and no problem saw found, I decided to investigate myself. After checking my spark plug wires, I found they were laying right on the manifold! So I replaced the wire that had melted. Once that was done I just moved my wires around to where they aren't laying on the manifold no more with a couple of properly places zip ties. If you want to see how it was done let me know

Thanks Nathan. I used all the factory split loom, wire holders and routing to make sure that didn't happen.

done just about everything may as well pick up some good plugs and a fuel filter. not so sure of good ones for 3.8 but get some good ones, even the 3.8 can be a pain to change plugs so the longer they last the better. could send injectors in and have em cleaned and flow tested. not a bad idea after 80 or 100k miles.

I used ACD Iridium plugs when I put my new engine in my 99 V6 and they preformed great. I also like to use Lucas Fuel System cleaner to keep my pintles lubed and fuel system clean. I put in about 6oz every oil change and it works great. If you think things may be dirty then put 6oz or so in every tank full. The 32oz bottle costs 2x what the 5 oz bottle does and it is 6x the ammount. You may also consider buying one of the single treatment bottles as a measuring bottle for your next time (I do this too). Sounds like you got the problem narrowed down to a bad plug or bad/dirty injector.

Oh and if you can make sure you lisence the car in your home state, VA loves to tax the pi$$ our of vehicles and they also make you do a BS yearly inspection before you can renew your tabs. This inspection is not very expensive but they check everything and 1 bulb being out can fail you (even if there are multiple bulbs for the same light). It is a pain trust me. When I was stationed there I kept my HoR as WA (no state income tax) and registered my vehicles to my Dad's address.

Massey

Thanks everyone, but I just found out some very bad news. 0 psi on the cylinder 2 compression check. (150 psi on cylinder 4). I'm guessing a broken valve spring is not allowing one of the valves to seat. Either way, I see MANY hours of wrenching, cussing and crying coming my way. How incredibly lucky for the guy who sold it to me!!