I’ve got a 92 RS Camaro with a 98 L31 vortec swapped in with a tuneport. Here recently, it’s had a hard start and has a stumble on throttle application and likes to “hang” when it revs down. It used to be real snappy and quick, but now it acts like it wants to fall on its face. I had 4 plug wires off the other day and mistakenly fired it up while they were off, I quickly shut it off and fixed the firing order, but since then it’s ran horrible. Would this be a possible timing issue? Or something else.

 

I mean, this may seem obvious but, did you put the wires back on in the right order?

 

I did, double checked it today when I started it up.

 

Also probably need to think back carefully about everything you did. If it was running good before, something obviously changed.

Did you take out any of the plugs? Possibly cracked a ceramic body? Are the plug wires touching exhaust and maybe got damaged?

Example of something stupid... one time i pulled a plug out an accidentally dropped it. Ceramic looked ok but I didn't notice that the electrode gap nearly closed due to the way it evidently hit the ground. Didn't realize it until I put it back in and noted the misfire, prompting me to remove the plug again, at which point I found it.

 

none of the plugs were removed, just the ends from the cap were removed. I’ll check them tomorrow and check back.