I have a 1986 late model that I threw a 35k miles motor in about 3 weeks ago, last night I brought it to WOT and it was popping on acceleration, I immediately thought that maybe my timing has been off and I’ve soiled a spark plug or two, but the spark plugs are just fine, my wires look okay, I have been having some random shut offs on the highway and figured that issue is an ICM but a bad ICM wouldn’t cause popping (whether rich or lean) on acceleration or just a misfire right??? A bad ICM just makes your motor quit I think.

I’ve been having a cold starting issue as well, it takes extra key turns to prime the rail, I got a code for “low fuel circuit voltage” I think it’s a code 13… however I have a new fuel pump as of last year along with a new filter, I don’t have any leaks so what could be the issue? Maybe the code 13 and popping/missing are related? Whenever I restart the car the code 13 goes away and starts like normal bc the rail is full, also when it was popping/missing on WOT I didnt get a SES light, it was also having a weird idle in gear and fluctuating from 600-900rpm (definitely related to missing)

I just really don’t wanna dive into a fuel pump again what could be the issue? I’m gonna start with new plugs tonight and if that doesn’t solve it I’ll move to ICM, if not that my mind goes to bad fuel pump.

update: fuel sniffer went nuts on the FPR vacuum hookup, could a faulty FPR diagram cause that code and fuel starvation, it most definitely could be my cold start issue

just discovered a burnt plug wire boot, so maybe that’s my missing issue, and the FPR is my cold start issue, gonna try both and see if I’m good to go