Interesting Problem

[darisb]

When I first bought our 92 K1500 (5.7l), the SES light on. I pulled the code, and it indicated that the Ignition Control Module was bad. I replaced it and the SES went away. I replaced the plugs, PCV valve and air filter and took it in to have is smogged. It failed.

 

The center contact of the rotor looked worn and burned, so I replaced the cap and rotor. After having driven it a couple times, I noticed that it ran great when it was cold, but when it warmed up it idled rough and eventually stalled in drive with my foot on the brake. It seemed to idle ok in neutral or while driving.

 

I took it back to the shop to figure out why it failed. I suspected the cat was plugged, because there was a slight odor in the cab when the motor was warm. Sure enough, they found the cat plugged and replaced it. This time it passed the smog, but they said it was losing spark. The shop said it was likely the pick-up coil (stator) in the distributor, but with labor included it was only a couple bucks more to put a complete rebuilt distributor in then taking the dist apart to put a new pick-up stator on it. The smog guy did remind the counter guy that if we don't fix "the miss" it will ruin the new cat. It makes sense to me to get a rebuilt distributor, but does it make sense that the pickup stator could be causing a spark miss?

 

Daris

[guyno]

When I first bought our 92 K1500 (5.7l), the SES light on. I pulled the code, and it indicated that the Ignition Control Module was bad. I replaced it and the SES went away. I replaced the plugs, PCV valve and air filter and took it in to have is smogged. It failed.

 

The center contact of the rotor looked worn and burned, so I replaced the cap and rotor. After having driven it a couple times, I noticed that it ran great when it was cold, but when it warmed up it idled rough and eventually stalled in drive with my foot on the brake. It seemed to idle ok in neutral or while driving.

 

I took it back to the shop to figure out why it failed. I suspected the cat was plugged, because there was a slight odor in the cab when the motor was warm. Sure enough, they found the cat plugged and replaced it. This time it passed the smog, but they said it was losing spark. The shop said it was likely the pick-up coil (stator) in the distributor, but with labor included it was only a couple bucks more to put a complete rebuilt distributor in then taking the dist apart to put a new pick-up stator on it. The smog guy did remind the counter guy that if we don't fix "the miss" it will ruin the new cat. It makes sense to me to get a rebuilt distributor, but does it make sense that the pickup stator could be causing a spark miss?

 

Daris

the pickup coil in the distributor tells the coil when to spark on each cylinder the shop that i worked at would replace the module and pickup coil at the same time or we would not do the job. if the module went bad the pickup coil is going to go soon if not at the same time

[darisb]

Sounds reasonable to me. Thinking I'll save myself some hassle, and pickup a rebuilt distributor. Hopefully I saved the old Ignition Control Module.

 

Thanks,

Daris

[Black Bart]

I replaced the distributor in my 94 becaused the magnetic rotor had cracks in it, I bought a rebuilt one from AutoZone for $93.99 complete with ICM module, Cap, and Rotor with lifetime warranty.

[darisb]

So the wife and I picked up an rebuilt distributor Saturday morning. 45 minutes later the truck was purring. Thanks everyone.

 

Daris