Hello again. I first wanted to thank Gorn and a few others who have given me the information to get to this point.

To sum what has been done so far.

Bought a 95 3800 series Camaro running pretty crappy. Misfiring, overheating and stalling (of course that didn't start entail the deal was finalized).

Okay so I just got done redoing the intake and head gaskets (which the intake was really, really bad). Found and replaced:

Cracked vacuum lines
PCV valve
Oil level Sensor

Now I got the car back together and fired it up last night and the fuel gauge now works (never did before, weird). Overheating problem fixed, no water leaking (yay)!

It still is misfiring but not nearly as bad. Before it was reading multiple misfires from the computer, now its just reading cylinder 6 misfire. New plugs, and wires installed. I thought maybe an EGR problem so I took it off, cleaned it (which is didn't look that bad) and then put it back on. No change.

My brother (who is also a mechanic) doesn't think its the EGR due to it only being one cylinder and not multiple. How do I pinpoint this problem? It could be bad coils, injector, fuel pump/regulator or something completely diffrent. Any way to narrow this down without throwing parts at it and hoping I guess right?

 

Swap the coil that has the cylinder #6 plug wire with one of the other two coils. Make a note of which terminal was #6 on the coil, and see if your misfire moves to the new cylinder that coil is now firing. If it does, get a new coil.

 

Okay so coil packs tested, super strong spark. I did both the swaps and the spark plug test. The misfire didn't seem to change regardless of what cylinder I had unplugged while running which is weird.

I also noticed a massive power drop when a misfire happens (lights dim, etc.) but that just might be because the engine is trying to die. I checked the alternator and battery at an auto store just to make sure and they checked out.

Why would the misfire be the same regardless of what spark plug wire is off?

Next injectors I guess?

Thanks again

 

The injector would be the the next place to look. Get a set of NOID lamps and see if the #6 injector is being fired. The lamps won't tell you if the injector is good, but they tell you if the signal from the PCM is getting to the injector. The next step would be to do a compression test and see if that cylinder is viable.

Pulling the wire off the plugs is an old school trick which was OK back then, but not a good idea with electronic ignition systems, as it can cause arching and damage to the ignition components.

 

Alright, after a long frustrating night this is what I have learned.

The Idler Control Valve was bad, replaced it with no real improvement over the misfire.

Compression check came out good.
Fuel Pump and regulator working right.
Injectors are good.
Coils, spark plugs and wires are good.
Alternator and Battery tested good.
Fuel filter recently changed.

I am at a loss what is causing this now. Its still misfiring on cylinder 6 and it has very limited power. It will backfire when you try to accelerate hard. Any ideas?

 

ddouble tripple check that the plug wires are in the right places. have the injectors cleaned and flow tested at an injector shop.

 

Make sure the plug wire isn't grounded out anywhere. Swap the #6 wire with another and see if you still have a misfire on 6. Btw, a poor flowing (clogged) injector won't show up as a cylinder specific error.

 

Did that. swapped and then changed wires just to make sure.

 

yah 69 i was thinking it couldnt be the injectors and it must be a bad connection or wire to the coil.

 

There is an off chance that the ignition control module has a problem. Usually the ICM affects all cylinders, but being you tried a whole bunch of stuff, get the ICM tested at a parts store. The ICM is under the coil packs.