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Semi and equipment diesel mechanics please read

ktmoutfront

ktmoutfront

We live in the stupidest times.
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I am having issues with my Cat C-12. Blew the ECM fuse last Saturday. Did not know this until I had it towed home. It was dark and cold so I could not deal with it. Started and ran just fine.

Went out to start it today to move some equipment, no joy. It seems to run on a few cylinders and does the blue unspent smoke blowing. The check engine light goes on and off. More on than off.

Where should I start?
 
Is this the engine in your freight shaker?

Blue smoke as in burning oil blue? Or unspent smoke like unburnt fuel smoke?

Is the truck/engine mostly stock or are there some add ons/mods?
 
Bone stock. Runs on some cylinders and looks like un-burnt fuel. After reading for hours on line, it looks like it might be a fuel delivery issue. No throttle response either.
 
Change your fuel filters and see it runs better.

As far as the ECM, check your grounds first.
 
without having someone read the codes its just guessing, but with that said. if the filters don't fix it, let it run for a while and hit each cylinder with a temp gun, that will tell you if or which cylinders are cold.
 
I just read how to read the codes by flipping switches and swing a dead chicken over my head. I hope to work on it tomorrow afternoon.
 
The blink codes?
I wonder if something with the fuse blowing screwed with the ecm and it's causing over fueling in some cylinders. Cats are can be real sensitive with power to the ecm. I know some of them won't even start without adequate voltage at the ecm. They'll crank, but won't start.
 
Sounds like it might be something with the high pressure fuel pump. Most of those are electric. Plus most of those injectors are electric and could probablly pop a ecm fuse. Out this way most dealers will talk to you over the phone and are glad to help diagnois it. Try given a cat dealer a call and talk to the service department.
 
Did not get to touch it. To late to get started and it has gotten cold out.

My local dealer sucks for helpmlike that.

I am going to start by checking the fuel filter for level of fuel. If it is not full, something may be up before it. Then I am going to check presure after the lift pump and go from there.
 
Got some time to mess with it today. Batteries were totally drained. Never happened before with sitting for months on end. Charger was added for a couple of hours and the Jimmy with its high output altenator was put to use.

When I took the positive cable off of the batteries, it had a heavy draw arc? Now what? Pulled the fuse that blew. Heavy draw arc went away. So something is staying on and drawing power.

Does the same running issue still. I check every time I touch something.

As it is running rough, I do a little shot of juice and it runs on it fine.

Did the dead chicken over my head thing and ended up with 4 codes. 71-ignition fault, 72 through 74 are injector low voltage.

Had to put a new ignition switch in as mine locked up, was going away anyway.
 
I can't say for truck engines but with the marine Cats I work on (first its usually a dead fish over my head lol but), most problems stem from bad connections or connectors. I'd start there or look for some wiring that may be chafed and grounded out.
 
Most of the time spent on it yesterday was doing that. Fuse panel is hanging out. A bunch of stuff is laying in the camper from under the hood so I could get the the wiring. So far, nothing obvious.
 
Not sure but does that engine have a valve cover gasket with the electrical connectors going threw it ???? Kind of like a power stroke.
 
Might be a bad ECM. If it was one of my trucks, I would just call "the guy" out and have him plug into it. He will know if it's the ECM acting up or not. It's not uncommon for these block mounted ECM's to take a dump, and act weird in the mean time.
 
When I get back in town, the new reader will go on. If it does not give me enough info, a guy will get called.
 
Update.

Codes show low voltage to injectors. After going through everything else, a caterpillar tech walked through everything I checked and with the codes we determined that the injector control module is bad. Sucks as it is part of the ecm. So I just spent $1100 on a reman unit. I hope I am right.
 
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