@ a loss! gets warm and dies code 42

[a162843]

1991 lumina euro 3.1
car died on me, could not get it to start. had fuel pressure and spark. I replaced the icm(the modual the coil packs connect's too), cps, fuel pump and filters. still nothing. I then replaced the map senser, still nothing. i then replaced the o2 senser then voila it started, but ran crappy. so i replaced the plugs and wires, now it runs better then when i bought it, but now when it get's warm it dies and gives me a code 42. if i let it sit 15 min or so it starts right up with the code gone. HELP!!!!!!!!!!!!!

[bigtimmy45]

in my book a code 42 is: 1) Electronic spark timing (EST) circuit - open or shorted; 2) Direct ignition system (DIS) fault - bypass circuit open or shorted to ground during engine run; 3) Fuel cutoff relay circuit - open or shorted to ground

I am not a mechanic but that is straight out of the code book - if anyone can help him figure out how to check these things, I am sure he would be greatly appreciated

FYI, I had a similar situation but mine was fixed with replacing the ICM, cps, coil packs, plug wires and plugs and that was all - I have the 2.5L 4cyl in a '90 lumina that now runs great at a little under 220,000 miles with no oil leaks, no oil burning and no coolant leaks - sounds like yours is more than mine - hope this information helps a little

[BEAVIS18]

yeah i have the same code on my 92 3.1 some help would be nice

[richtazz]

A code 42 is the hardest OBD-I code to properly diagnose. Most times it is caused by a bad CKPS (CranK Position Sensor) and/or the wiring to it, or a bad ECM. DIY tests include the ECM "tap test" which consists of lightly tapping on the ECM case (preferably with the plastic handle of a screwdriver, nothing metal) while the car is running. If the car stumbles or dies, the ECM is a likely cause. The other is a visual check of the wiring that goes from the CKPS to the ICM. It goes from the back of the block, under the harmonic balancer, and across the front of the block to the ICM. On it's way, it runs very near many moving (RF CV axle, harmonic balancer,) and hot (both exhaust manifolds) parts and can be chaffed or burnt or damaged by road debris if it came loose from it's factory restraints and is hanging down.

[a162843]

Hey thanks for the ideas. I'll try them when i get home and post my findings.

[a162843]

egr was cogged up. i cleanded it and hit hasnt stopped yet.

[bigtimmy45]

hmmmmmm - someone suggested I clean up my egr too to get a stutter to go away that began immediately after I replaced my ICM - I am also gonna replace anyway the TPS and the IAC eventually but not immediately - I will do those as time and money allows

isnt this a great forum?