I was reading where someone replaced the head and it solved the problem for them. So check intake for leaks aswell. Then have a beer. Or have a beer then check for leaks.
FIXED!!! Bad ECU - Runs rough, CEL and P0304 (5 Viewers)
- Thread starter Jeff Elliott
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- Thread starter
- #82
@Red Merle - You are right that I do have one of those and it wasn't hooked up. That said, I just went out and hooked it up and she still idles like a Peterbilt.
It was a good try!!!
It was a good try!!!
I don't know how I missed this thread. I have an extra 97 ecu just over the 150 bridge from you.
I fly out in the morning for work and can't help you this week but if you still need help next week or want to borrow the ecu let me know. You can grab the ecu today if you want so you can have it to test this weekend. Just let me know
I fly out in the morning for work and can't help you this week but if you still need help next week or want to borrow the ecu let me know. You can grab the ecu today if you want so you can have it to test this weekend. Just let me know
Dang! OK, what about your wire splices? How far did you go when you inspected the area where you repaired it? Could you have crossed a wire or missed a section that was damaged?
Hmm, why was that ground not hooked up?
- Thread starter
- #86
Great to meet you customcruiser - I'm in the same boat (flying out on Monday). I have a known working ECU that arrives on Monday as well so when I get back on Tuesday I can plug it up and see what happens. Thanks a ton for the offer and I might just have to take you up on it!!!
That's a possibility... But the new length of wire running outside the truck from the #4 injector pulse wire plus a new injector plug for #4 plus pulling +12V from the adjacent injector wire eliminates any wiring fubars I could have made when reconnecting everything.
This is assuming that all the +12V injector wires that are all black with a red stripe terminate in the same place - in this case the 7.5 amp fuse inside the cab... If that's not the case, all bets are off.
I unhoooked it when I repaired the wiring and pulled the harness down - just forgot to hook it back up but have done so now.
Thanks Gents!
I am not a wiring expert by any means and can't offer much in the way of troubleshooting beyond what has been discussed already, but I think I would try putting the truck all back together the way it is supposed to be set up and remove the ECU for a few minutes. It seems possible that some of your assumptions might be wrong. After you fixed those wires, what did you do? Did you try resetting the ECU? It seems like you have a bunch of stuff linked up that might not be hooked up exactly the way you think you do.
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IIRC, wires were shorted together at the EGR? Depending on what wire to what wire, it could have taken out the injector driver in the ECU. Trying this would confirm or just swap a known good ECU?
You could always take it to a good shop instead of selling it if the ECU doesn't pan out.
- Thread starter
- #90
@Red Merle - I can for sure do that. The truck sat for multiple weeks without the battery hooked up... Would that reset the ECU?
- Thread starter
- #91
Thanks Tools R US - That's the plan, swapping in a known good ECU on Tues with fingers crossed!
- Thread starter
- #92
I'm mulling over that option now... If all these attempts don't fix it then either 1) it's something simple I'm overlooking or 2) it's a deeper problem that's going to cost a lot. Hopefully the former!
Just remember it's a machine and it can be fixed. If I were you I would confirm 100% for sure whether or not spark is going to that cylinder and if it is, look at replacing or rebuilding the head.
- Thread starter
- #94
Thanks for those thoughts - How would I verify spark other than the inductive timing light?
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If the injector isn't clicking, that cylinder isn't going to fire, spark or not.
- Thread starter
- #96
Injector is most definitely not clicking - all the others do... This has to be the ECU!
You're right. Sounds like it's the ECU or the wiring.
OP have you made sure the connector that plugs into the fuel injector is good?
- Thread starter
- #98
That should reset the ECU. I guess you'll have to see what happens when you install the new ECU. Good luck and fingers crossed!
- Thread starter
- #100
Well, folks, it's fixed!!!
Got an ECU from @ccslider (thanks again!), plugged it up and no more diesel idle!!!
Just took it for a test drive and, although it doesn't run perfectly smoothly (likely because the ECU is learning), it runs a million times better.
Now I have to remove the bypass wiring and plug it back in to the original harness but I've got renewed energy to do so now that she runs right.
Thanks to all who helped and who had patience with me as I tackled more bananas than I've tackled before and on the first go!
Jeff
Got an ECU from @ccslider (thanks again!), plugged it up and no more diesel idle!!!
Just took it for a test drive and, although it doesn't run perfectly smoothly (likely because the ECU is learning), it runs a million times better.
Now I have to remove the bypass wiring and plug it back in to the original harness but I've got renewed energy to do so now that she runs right.
Thanks to all who helped and who had patience with me as I tackled more bananas than I've tackled before and on the first go!
Jeff
