1995 quad four engine miss

[Dennicorco]

1995 2.3L quad four has stalled and runs rough when restart is accomplished. was told by GM dealer needs ecm, coils cat convertor and most likely ign mod. had car towed home. checked ign mod which tests good,replaced coils,car now will idle but still has engine miss. Occassional serv eng light on. tried known good ecm, no difference. There is exhaust coming out of tailpipes ruling out a bad convertor, Not sure where to go from here. Coil hosing checks out with no open circuits. Does not appear burn't or show tracking of any kind. It is white and I am told this is a new replacement for the original. Vehicle has 167K on odometer and ran terrific prior to all this. only previous symptom of note was rough idle at start at start for about 1 minute then vehicle ran smooth. Any help will be greatly appreciated

[GTP Dad]

Clean or replace the Idle air control motor. Sounds like it is going bad or could be carboned up.

[Dennicorco]

Ok, cleaned the IAC, no change. Now I do know that the two spark plugs on the driver side of vehicle are not firing. Wet with fuel when removed. Is it possible we have an arcing coil housing between the circuits?

[skibum1111]

Most definately. Try cleaning it with windex, make sure its dry before you put it back on, see if this fixes it. This is only a temporary fix, the housing is probably cracked. Good luck.

[Dennicorco]

Please and Thank you. good point. well, I am done for the day. dropped coil housing bolt into #3 cylinder thru spark plug hole. any short cuts B4 we tear the head off this thing will be real helpful. thanks to those who offered help up to this point.

[GTP Dad]

Try an extendable magnet. You should be able to find one on the end of a screwdriver that extends and you may be able to get it out by running the magnet into the cylinder and moving it around. Otherwise the head would have to go.

[Dennicorco]

Thanks you all for assist. got the elusive bolt outof cylinder. Still running on three cylinders. Coil Housing helped and I can at least move car aound. I am almost ready to take back to shop. Am trying plugs and boots before I give up.

[Dennicorco]

Saga continues, I have now replaced Coils, tested Ign MOdule, replaced Coil housing and Plug Boots, tired switching ecm with know good unti. I still have a miss on one cylinder, seems to go away at about 1600 RPM while in park but is ever present under load.going down the road. Stumped at this point.
Thank you for any help

[GTP Dad]

Do a compression test on the engine. It is possible that you have an issue with a valve or rings in one cylinder. A compression test will give you an idea of the internal engine status, since misfires can be caused by just about anything it could be a bad head gasket. Finally, it is possible that you have an injector going bad. Try the compression test first, easy to do and inexpensive.

[GAfan]

try your o2 sensor, same problem happened with my 94 blazer and it was the o2 sensor

[Dennicorco]

Finally!! The dilemma is solved. I guess its back to basics for engine misses. the remedy was a new set of spark plugs. One of the four new ones I replaced was bad.....!!

thanks again and best of luck to all.

[GTP Dad]

What type of plugs did you use?

[Dennicorco]

I got them from my local GM dealership. Blue box, I think AC Delco

[GTP Dad]

If you have the plug take it back. It should have a guarantee if it isn't damaged. It is odd for a new plug to fail but I guess anything is possible.