graphiciron

Have a 1993 Grand Cherokee Laredo that has an intermittent misfire. It's pretty consistent... meaning it does it from start, hot or cold, park, neutral, or drive, throttle or no. It's intermittent because it sputters at irregular intervals. It's not throwing any codes either.

The whole motor is brand new. I have replaced pretty much EVERYTHING. It will be easier to tell you what i haven't done to it.

NOT DONE:

fuel pressure reg
distributor (mechanical parts)
fuel pump
IAC
O2 sensors
Cat
injectors (but I cleaned the hell out of them when I built the motor)

DONE:

Everything Else

I had the smog place sniff it, and everything is good except the HC... big surprise with the miss, but I don't think my cat is going bad....yet.

I'm going to start by looking at the plugs to see what they look like tonight. I'll check the wires for leaks also... even though all of that stuff is new.

I need a direction to go, otherwise I see myself checking and re-checking brand new parts.

PLEASE HELP!!!

Programbo

I guess I'd look at injectors and plugs first since that is easiest and the usualy causes of a misfire.

graphiciron

Ok now I feel stupid!! Maybe I should have done some investigating before I post a problem... so I took the plugs out and behold!!.... #3 plug electrode was bent all up!! I feel like a rookie by not checking the plugs before installing them!! After rebuilding the motor from the block up, checking and rechecking ALL clearances, and ALL procedures.... I don't check spark gap!!

Cleaned plugs, re-gapped plugs, viola!!!! Problem fixed!!