Tuneup gone wrong

[Irongiant]

I recently attempted to do a tune up on my 1992 K1500.
The usual, plugs ,wires, cap ,rotor, and while the cap was off I replaced Spark control Module.

After this routine the truck stumbles ,has a bad miss, and idles like crap.
I did get a code 43 (Spark Control Module) and replaced it, now no codes
but no improvement.

I have owned this truck since '96 and have done this procedure every two years whether it needs it or not.
I am at a loss as what happened.

I understand diagnostics are slime on line but any thoughts that would be helpful
would be appreciated.

 

[smdk2500]

did you by chance when you reinstalled the wires on the cap get off by one or acadently swap 2 of them around? I know it sounds simple and even though you done it numerous times accidents . Ive done it ive also got the fireing order right but had it going the wrong direction.

 

[Irongiant]

Thanks I thought that at first, but it's correct.

 

[RichLo]

If it was running fine before and this was just preventative maintenance I would go back to the originals one at a time until it gets better. There's obviously a defective part somewhere, I would bet its either the cap or one of the plug wires.

 

[NightRunner]

I had this issue once, turned out that I got a bad batch of spark plugs. Put a new set in and it ran like a top.

 

[884x4310ci]

I would also lean towards bad wires.

 

[skylark]

I'd suspect a bad cap. I've purchased several.

 

[wheelman]

I recently attempted to do a tune up on my 1992 K1500.
The usual, plugs ,wires, cap ,rotor, and while the cap was off I replaced Spark control Module.

After this routine the truck stumbles ,has a bad miss, and idles like crap.
I did get a code 43 (Spark Control Module) and replaced it, now no codes
but no improvement.

I have owned this truck since '96 and have done this procedure every two years whether it needs it or not.
I am at a loss as what happened.

I understand diagnostics are slime on line but any thoughts that would be helpful
would be appreciated.[/Q

Did you use aftermarket cap and rotor.i did that once learned my lesson went and bought the dealer parts.and all was find.