misfire? 93 mkviii

[TicTacTone]

i'm getting a stutter in low rpms (1k to about 1400) and on the highway doing about a 70 or so the check engine light comes on and off, but its perfectly smooth. when i parked it tonight it was off and had been for about 15 minutes, anyway, i just put new plugs and wires in (last week less then 300 miles on them). i'm curious if its a misfire or a tranny problem, my tranny doesnt feel like theres anything wrong and has fresh mercon v. wondering if anyone else has come across this in the past and what it turned out to be. its obd1 so it doesnt store codes so i cant exactly scan it right now to pull a code lol otherwise i wouldve.

 

[kustomizingkid]

I'd look for vacuum leaks.

 

[Calabrio]

I've got a shutter at low RPM, high load situations. Like around town, low speed traffic or slow hills.
Cause: Leaking o-rings in the IMRC.
Hope that's not the problem because it's impractical to fix.

 

[TicTacTone]

^^that actually sounds like exactly whats happening. i was thinking maybe fuel filter but that just doesnt seem right to me...does it hurt anything to keep driving it with leaking o rings on the imrc? and is there a way to fix it or is it once they go they go? i'm new to the 4.6 dohc...i'm a 5.0 guy at heart lol and the only real experience i have with a 4.6 are new edge mustangs and crown vics...as far as the vacuum leaks go i already checked for any and couldnt find one. i also checked my fuel pressure and regulator and its all good....if it is leaking o rings as long as it doesnt hurt the engine driving with them leaking then i dont really have a problem driving like that, most of my driving is above 1800 rpm anyway and its smooth at that point, i just noticed it when doing like 45-50ish when the car is sitting it a low rpm and when i first step on the gas it stutters a little...kinda like a very minor misfire...but as soon as i start moving it goes away until i let off the gas a bit and it shifts and the rpms drop down again.