i have a 93 park ave 3.8 vin l check engine light is off but it shows a code23 at times it will run perfect and others it misses at all speeds i have changed feul filter spark plugs and wires iat senser crank sensor and balancer cleaned ecm grounds tried coils ing module ecm and also replaced upper and lower intake gaskits please if anyone has any ideals what going on please let me know thank you

Have you tested your fuel pressure?

ya sorry i forgot to add that i check feul pres it was right with specs and i also checked vaccum lines and i sprayed around the intake no change this thing is driving me crazy when it runs good and next time it missing grrrrrr

Weak coils can cause a misfire. I've had coils test good, and misfire. Put in new coils and the mis is gone.

ya i put brand new coils on it still the same

Possibly cheap wire set or cracked plugs?

Misfires can be caused by bad plugs, bad plug wires, bad coil, bad ICM, bad fuel injector(*), low fuel pressure, burned or bent valves, broken valve spring, bent push rod or rocker. Go threw each.

wouldnt u think if it was something inside the motor it would do it all the time?theres times it runs just fine the car does have over 300k on it

hey guys think i found the problem found some burnt wires that goes to the crank senser thanks for the help

COde 23 is MAT and IAT circut low temp..

Mat (manifold air temp)
IAT ( intake air temp)