Code 42 Missfire/ECM

[samsquanch]

I have a few questions about this.

A few weeks ago I installed a new ignition control module since mine was goopy when warm, and to solve a random minor missfire issue at idle. Nothing had changed after install. Reset ecu and car ran and started much better but still minor random missfires at idle.

This morning its like 35 degrees so I want to go for a drive. After starting and idling decent for a few minutes. Car starts sputtering halfway up the street and dies when slowing down about 5 times on the way home after that. It was starting to not cut out as much so I baby it around the neighborhood and starts running better but seems low power. Got home. When I restart it engine light is on. Pulled code 42.

One cause listed is prom not seated correctly. So I went ahead and reseated both chips to try and improve connection. Started the car and idles better than ever now. Went for a drive and seems to run better and have more power than ever before.

My questions are is how many failures does ecm need to set a code? Has anyone experienced chip connection issues? Could the new ignition module be causing this even though there was no difference after changing? Is there something I could be missing here?

 

[TurboTGuy]

Gasolines have changed a lot since 1986/1987.

If you are still running the original chip in the ECM, it might be time to get an updated one from Eric at Turbo Tweak.

 

[salvageV6]

Only takes one time for the conditions listed on this page to set a code. Do you have a translator on the car one with timing mods. done on the white wire?

 

[samsquanch]

No timing mods. Car is bone stock.

I havent worked through this tree yet. But Im thinking ecm or chip is faulty.

The reason is because I havent seen the ses light until now. Even when turning key on. Now after this code shows up ses light works fine with key on. I spent some time this morning after resetting ecm. Car would start but not run about 5 times. That was new. Last attempt I gave it a bit of gas, it stumbled the code showed up then ran fine in limp mode.

I have to rule a few other things out first, but Im thinking ecm problem. The reason is even with the new ign module it ran the same as with the old goopy one. Its possible the new module has malfunction internally and threw this code, but the inital problem might have been ecm not controlling timing properly all along. Another reason is the car runs noticably better in limp mode.

One thing Im trying to figure out. This morning I opened the ecm looking for anything obvious inside and noticed one of the boards had a kindof swiggly stuff going on in the printed circuits. Im not sure if thats normal or not. I would need to look at another one to see. I scraped at it in a spot but didnt seem to flake off, or appear corroded.

Im thinking of biting the bullet and buying one to try out.

 

[TurboTGuy]

I have one you can test with, if you need it. Equipped for a powerlogger, too.

 

[Lockman]

Went through these troubles last Summer. Try pushing eve in every connector pin on your ECM ' s A & B harness.

 

[samsquanch]

Ok followed that tree. Determined ignition module was bad. Swapped in my old goopy one and back to running good again. No code 42.

I think the fuel/timing map in limp mode makes it run better at idle/low throttle. Thats why it felt like it was running so good.

Kind of pissed that module was new and only lasted 30 miles or so.

Strange thing is. Now cel shows when key on. Not sure why it didnt do that before all of this.

Please point me in the right direction for a new module. Mine becomes goopy when warm. I dont trust it.

 

[TurboTGuy]

I have a couple used "known working" modules on the shelf.

I went with a TR6 setup not long ago, so I have no use for them.

 

[samsquanch]

How much? What brand?

The standard brand didn't last me but 3-4 drives. I'm trying to get it warranted.

I just wish mine didnt get goopy when the engine is warm. Aside from that I would run jt.

 

[TurboTGuy]

The one I'm looking at has no name brand on it.

It was road tested in September of '16 and has been wrapped up, boxed, and sitting on the shelf in my garage in Phoenix since.

Pay for shipping and it's yours.

 

[samsquanch]

Dm sent. I will take it.

I think seller is sending a replacement, but a spare cant hurt.

 

[TurboTGuy]

Sent UPS today.

 

[samsquanch]

Thank you! Im glad to be a part of such a friendly support group.

 

[samsquanch]

Merry Christmas!

TurboTGuy made it onto my christmas tree.

Thanks for the help. Im back on the road.

 

[TurboTGuy]

Ha!

Cool, thanks. Glad you got it going.