Hi guys, I'm new to this forum and I need a little help. I have a 2000 S10 4.3 with 155K on it that has been well mantained. At around 50 K it started missing under load and I did the usual tune up with plugs, rotor and new dist. cap and it still missed. Checked the wires and they were in great condition. Had a friend look at it and he saw a burned spot on the coil. The inner part of the coil was arcing on the outer part. replaced the coil and it ran great, for a few months. After the second one went south I checked the ground wires from engine to body and the battery cables. it ran fine for a few monthes and then burned another coil. I'm on number 6 now and it's lasted only 2 monthes and missing worse than ever. There are no codes showing on the diagnostics, I'm stumpped at this point, a little help would be appreacited.

Might be a long shot but maybe the ignition module is giving the coil too much dwell or something and eventually overheating the coil. If you had a Tach/dwell meter it could tell you.

Hi guys, I'm new to this forum and I need a little help. I have a 2000 S10 4.3 with 155K on it that has been well mantained. At around 50 K it started missing under load and I did the usual tune up with plugs, rotor and new dist. cap and it still missed. Checked the wires and they were in great condition. Had a friend look at it and he saw a burned spot on the coil. The inner part of the coil was arcing on the outer part. replaced the coil and it ran great, for a few months. After the second one went south I checked the ground wires from engine to body and the battery cables. it ran fine for a few monthes and then burned another coil. I'm on number 6 now and it's lasted only 2 monthes and missing worse than ever. There are no codes showing on the diagnostics, I'm stumpped at this point, a little help would be appreacited.

Make sure your plugs and plug wires are good.
If spark can not go threw plug wires and plugs it will go/jump out someplace else like threw coil.

Also cap and rotor and camshaft retard setting should be checked.
Any check engiune lights or codes or kick back when starting?

Also cap and rotor and camshaft retard setting should be checked.
Any check engiune lights or codes or kick back when starting?
I changed the plug wires about a year ago and they still look good, checked with an ohm meter and tested good. Cap and rotor were changed at the same time, haven't looked at them since. Never had a check engine light and it's always started good, just hit the switch and it's running. I changed the plugs yesterday, even though the old ones looked good. probably 60K on whats supposed to be 100K plugs. Installed a new coil today and it appears theres another problem, because it still misses. Not as bad but still not right. Going to have my friend check it with a scan tool tomorrow. I'll check the cap and rotor first. Thanks for the replys, I'll let you know what I find out.

If it is missing that is your problem.
You can not tell by looking at or how old plug wires how good they are.
Test them out.
Check for good hot blue spark to all plugs.

Also check camshaft retard setting.

If it is missing that is your problem.
You can not tell by looking at or how old plug wires how good they are.
Test them out.
Check for good hot blue spark to all plugs.

Also check camshaft retard setting.
What is the cam retard setting? If you mean the timeing then it's right. Took it to a friend who has a scan tool and nothing showed up. He told me he thought it might be a ground problem and thats what I thought from the start. Drove home and started with the battery cables, they were good. Started to remove the engine to body cable, thats a stud welded to the body over the heater, and it twisted out of the cowel. It was rusty almost all the way around, just a very small part was carring all the current. I looked around to find a place to attach the ground cable and found none. I removed the plastic cowel cover and reached through the opening in the upper cowel and could feel the hole where the stud pulled out. I ran a stainless quarter inch bolt with a star washer through the hole and and nutted it with a stainless nut that has a serrated washer and tighened it, replaced the ground cable and the miss was gone. I made another ground cable from 8 guage wire and installed it from a good spot on the rear of the intake to another stud on the drivers side that the hood grounds to. This cured the miss but I don't know about the coil, I think it will, I'll let you know in a couple of months. Thanks for your help.

There is probably something else wrong but try getting an ACdelco coil. BTW what brand are you using?

What is the cam retard setting? If you mean the timeing then it's right. Took it to a friend who has a scan tool and nothing showed up. He told me he thought it might be a ground problem and thats what I thought from the start. Drove home and started with the battery cables, they were good. Started to remove the engine to body cable, thats a stud welded to the body over the heater, and it twisted out of the cowel. It was rusty almost all the way around, just a very small part was carring all the current. I looked around to find a place to attach the ground cable and found none. I removed the plastic cowel cover and reached through the opening in the upper cowel and could feel the hole where the stud pulled out. I ran a stainless quarter inch bolt with a star washer through the hole and and nutted it with a stainless nut that has a serrated washer and tighened it, replaced the ground cable and the miss was gone. I made another ground cable from 8 guage wire and installed it from a good spot on the rear of the intake to another stud on the drivers side that the hood grounds to. This cured the miss but I don't know about the coil, I think it will, I'll let you know in a couple of months. Thanks for your help.

Good find on the ground.
Sounds like you may have found most of your problems.

Camshaft retart setting is the dist rotor position seting that points the rotor dead on with the plug wire terminal in dist cap.

If not set at on at 0 degrees or - or + 1 degree it will jump spark and cause a high voltage problem.

Cam shaft retard setting can be read out and checked with a high end engine capable scanner.

Do not confuse camshaft reatard setting with ign timing.
ign timing is preset on your engine and is not adjustable.

Good luck

There is probably something else wrong but try getting an ACdelco coil. BTW what brand are you using?
I use AC Delco stuff on my Chevy, Thank you.

The bad ground was probably the whole problem. I was assuming if you had checked out all the grounds and the secondaries were in good shape (plugs, wires, etc), then about the only thing that I could think of that would ruin coils is too much dwell at lower rpms. It probably was the hard to find ground problem all along.

The bad ground was probably the whole problem. I was assuming if you had checked out all the grounds and the secondaries were in good shape (plugs, wires, etc), then about the only thing that I could think of that would ruin coils is too much dwell at lower rpms. It probably was the hard to find ground problem all along.
I'll have to admit, the dwell never entered my mind. With these computer controled engines you just assume that things like that are taken care of. I apperciate your effort, Thanks guys.