91 Lebaron Codes 26 and 41, Engine miss

I've got a 91 LeBaron convert, 3.0 MPi that has a miss. Pulled the upper intake to gain access to fuel injectors and wiring. Check all the wiring and everything looked good. Installed a new Power module(SMEC?----I'm a GM guy) and the car started and the miss was gone.... For a few minutes. It returned along with the code 41. Pulled intake again and removed 4 wire plug and wired them direct. Some of the wires looked like they might be suspect. Put her back on, cleared codes, and same thing. It says to check the wiring going to the logic module. What and were is that. Also, I hope I didn't wreck the new power module.

There is a ground wire behind the power module that I want to sand and reinstall for good measure. I also replaced the battery cable ends that had seen days, no change.

Any help would be greatly appreciated.

Do a cylinder balance test, engine running. Kill cylinders one at a time while you note the rpms. If you kill a cylinder that has no effect on rpms, that cylinder is dead. Then you check fuel--spark--compression.

Also, check the charging system or have it checked.

I originally did check for dead holes. #5 was the one. Had spark and compression....swapped injectors and no change. After I installed the new power module the miss was gone for a few minutes. I'll check the charging system for exact voltage. Are they that touchy????

As far as the charging system, I just went by one of your trouble codes.

You may have to check amp draw for all injectors. If something caused the old pcm to fail, you need to fix that before replacing the pcm. The problem might cause the new pcm to fail,also.

I originally did check for dead holes. #5 was the one. Had spark and compression....swapped injectors and no change. After I installed the new power module the miss was gone for a few minutes. I'll check the charging system for exact voltage. Are they that touchy????


When you swapped injectors did the miss follow with the injector? I had same problem. dead miss with same two codes and it was bad fuel injector... went to wrecking yard got 6 injectors off a 98 voyager and put all of them on with new o-ring kit and miss gone, no CEL.

Also pull upper plenom back off and ohm out all 6 injectors. they should read cold/outside temp which is about 100 where i am somewhere around 20.0 ohms on the 200 scale. if they ohm out really high or infinite they are bad. I would suggest replacing all 6 injectors. I got my six, fuel rail, and wiring harness for around 80 bucks. I just cleaned them up with tooth brush and b-12 carb cleaner and stuck them in.

P.S. if you do have bad injectors when you replace them, you can use carb spray as a lube on the o-rings when pressing them into the fuel rail and the block. it will keep them from tearing and also when it drys it helps the o-rings to "stick" to the block and injector.

When you swapped injectors did the miss follow with the injector? I had same problem. dead miss with same two codes and it was bad fuel injector... went to wrecking yard got 6 injectors off a 98 voyager and put all of them on with new o-ring kit and miss gone, no CEL.

Also pull upper plenom back off and ohm out all 6 injectors. they should read cold/outside temp which is about 100 where i am somewhere around 20.0 ohms on the 200 scale. if they ohm out really high or infinite they are bad. I would suggest replacing all 6 injectors. I got my six, fuel rail, and wiring harness for around 80 bucks. I just cleaned them up with tooth brush and b-12 carb cleaner and stuck them in.

P.S. if you do have bad injectors when you replace them, you can use carb spray as a lube on the o-rings when pressing them into the fuel rail and the block. it will keep them from tearing and also when it drys it helps the o-rings to "stick" to the block and injector.

I'll have to check the miss again. Thanks!

I'll have to check the miss again. Thanks!


No problem. Let us know how it turns out. And what you figure out.

this problem seems to be really tough man!!!

this problem seems to be really tough man!!!

Yes it does, I learn something new every day.