i had a reman.engine put in by a respectable co..ran great for 2 weeks..stopped to pump gas engine stalls ..wont start..take it back to the shop..bad coil...long story short..Im on coil number 3 now..the other2 were aftermarket ..this time I went with a mopar..they usually last about 2-3 weeks and then boom...the last one to go..I had a check engine light come on 3 days prior..had it checked..code was for #8 cylinder mis-fire..after replacing coil..light is gone...also it has now started to miss on occasion to the point where it dies..and if it starts while your driving down the interstate its almost like its running out of fuel..I would appreciate any help guys..this thing is my main transportation..and Im scared to drive it anywhere..BTW the guys at the shop where I had the engine installed have been nothing but great..they have flipped the bill on the coils..and have hooked it up to the computer trying to find the problem but cant come up with anything..everything checks fine???

 

I would look in other places besides the coil. The alt or voltage regulator maybe something misconnected or loose in the harness.. Those should throw codes but I dont know much about the newer trucks as you can see from my sig.

 

One thing to verify is that the spark plug gaps are correct.

The other thing to check for is spark jumping to ground, as this will overheat andburn out a coil within the timeframe you specified. The best time to check for spark jump is at night when it's dark. The spark is a lot easier to spot if it's in a hidden spot like those metal towers that surroundthe plugs for example. The code for a misfire on #8 is a pretty good clue to look over that spark wire with a fine tooth comb.

The last thing to check is that the voltage across the primary side of the coil is within specifications.

 

I would agree with Alloro here.

If the engine coil is the basic OEM/aftermarket type and there are performance spark plugs and performance wires, the coil will burn out over a short time.

You could do one of two things here. Get a decent performance coil or replace the plugs with the regular Autolite plugs for that engine size/type/year and replace the ignition wires to a standard grade. About the performance coils, one brand really stinks and doesn't last long, but my memory fails to remember what brand that was.

Typically, no codes would to thrown when the performance plugs and wires are used with an ordinary coil.

How's the cap-n-rotor? Are those using cooper/brass contacts? If not, andit's aluminum, the contacts would burn up way faster, thus the issues of keeping the engine running. Again, usually no codes are tossed for this either. [&:]

Hope this helps some.