Hello Folks,

I have been chasing a firing problem for some while now. I first had plugs and COPs replaced. Before had misfires on cyl 1 and 8 brfore we replaced them. After we replaced them we still had same said 1 and 8 misfiring.
I replaced fuel injectors on 1 and 8. Still had same miss, running rough after placed in gear. Checked with computer and found missing only on #1 cylinder.

Swapped 1 and 8 injectors and cop, unplugged #2 injector, rpm falls off, worst idle than before. Unplugged #1 injector, no change in engine.

Removed plug on cyl 1 and checked gap, set it .054, and reinstalled, no help.

I have also replaced a few vacuum hose as well,, no help.

I thought I would run it by you guys before I gave up.

I could use some help.

thx in advance

 

Any ideas guys??????

 

Compression test. If a known good coil, plug and injector has been swapped and tested to be good then compression test would be next.

 

Thanks, I will get on with that next.

 

Plug up a good coil/plug to the affected cylinders and look at the spark.
If you don't see any, the PCM is not ground switching the coil as one possible cause.
Is the injector being pulsed?
I would do theses checks before doing compression.
If the compression is that poor in a cylinder you would hear the crank rotaion vary in sound.
Good luck.

 

Thanks Blue, I had not thought of that. I know when I pulled the plug it was clean, no oil, not wet either.