• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Desperate! Cranks but dies immediately. Run in limp mode.

Quick update:
No luck chasing wires.
Tried to do the KOKO process to get the engine to do a relearn. It is hard to do a relearn if you can't get it to crank.
I may have problems with the CPS. The one that came out of the engine, in pieces, was 10154687. I have read posts from matuva that he has been unsuccessful in replacing 10154687 with 12557046 and getting the truck to run. I will have to pull the new CPS and check the numbers to compare.
 
Update: still trying

:holyshirt: She still isn't going. Still havn't started replacing parts blindly. Can't afford to. Here is an update on what I have tried.


Put a clear hose from fuel filter to IP, No air in lines.​

Pulled the screen filter at inlet on IP and cleaned.​

Checked return line.​

Rechecked fuel shut off solenoid. It seemed to work properly. I pulled the insides of the Fuel shut off solenoid out and tried. Same same.​

Tried yet another CPS. Still no luck. All of them have had the same part number 12557046 on them. This is not the same as the original 10154687. Can't find any different part to try.​

She still cranks and runs sometimes. If you mash the accelerator while it is running it will die when it reaches 2000 rpm +-.

Most of the time it while crank and die immedietly.

Always have code 19 after it cranks, or tries to crank. Sometimes throws an 18 in with it. Oh yeah, Fuel gauge acted funny for a little while when I was working on it. It would peg all the way over. After draining the tank I only put back in a few gallons. She is lower in fuel than I have ever let her get before.

It always cranks and runs fine with optic sensor or CPS unplugged in limp mode.

Other things I am debating trying when cash allows in the order I may try them.

Remove intake. Check all wires from IP, sensors, ect, all the way back to as far as I can check. Remove old PMD while I am in there. Take the resistor out and put in newer pmd and see what happens. Replace return fuel line while I can get to it. Make sure return line is functional. Clean out the rest of the crap left by rodents. I found a huge nest of junk that had been there since before I bought the truck.​

Tear into the front of the engine and see if I damaged what the CPS reads from when I removed the CPS. Any suggestions? Replace timing chain front seal ect while I am in there. Could these problems be caused by a loose timing chain?​

New PMD or good used. Can't afford either yet. Anyone have a known good used they would sell cheap?​

Replace IP with a new or rebuilt. I hope this isn't it since it will be a while before I can afford it.​

All suggestions and help is greatly appreciated.

PLEASE HELP!
 
Last edited:
I would contact matuva by pm and see what he found out. I think you have a crank shaft position sensor problem. DO you have access to an oscilloscope?

If you do you need to check the CPS output and voltage. see if it is producing the voltage and square wave signal needed.

By the way my sentence structure errors are for your benefit. heheheheh
give me an e for effort though.
 
Checking CPS

Matuva and I have been communicating PM about the issue. Neither of us has made progress.

I do have access to an oscilloscope. How should I check it out? Unplugged completely? If I damaged something removing the CPS I should note a missing wave right? Could to much slack in timing chain confuse the computer when comparing CPS timing with OS?
 
KeepHerRolling said:
Matuva and I have been communicating PM about the issue. Neither of us has made progress.

I do have access to an oscilloscope. How should I check it out? Unplugged completely? If I damaged something removing the CPS I should note a missing wave right? Could to much slack in timing chain confuse the computer when comparing CPS timing with OS?
Click to expand...

You can back probe the connector or disconnect it completely which ever you are more comfortable with. If you can get it to run in limp mode do that and take a look at the wave should be square with five volt on off. I think the optic sensor has the one long count to show where top dead center is.The crank sensor only has four on off counts . Let me know what you have and we can go from there. :coolgleamA:

You can also read the optic sensor out put if you need to, to see if it is counting correctly, I wish GMCTD would step in on this one he is a true guru on the electronics part of this engine.
 
I'll be the first to admit I'm not sure if this will help but at this point I'll throw it out there. Has anyone suggested looking at the optical sensor for the oil sending unit? I thought I remember reading somewhere that these get gunked up and cause some of these symptoms. Thoughts?
 
Sounds like grounding problems to me, with likely connection problems where the main PCM harness runs across the ac evaporator lines into the cabin - start checking grounds and wiring down at the frame, firewall, between the block and the starter motor, etc - could also lilkely be the Inj Pump wiring harness, ~35bucks from most vendors - current version should be teflon-insulation with silvered wiring in crimped and soldered connectors - and that ground must never be removed from it's oem perch on the top corner of the IP, unless you're replacing the harness
 
Good to hear from you (GMCTD) been awhile since we have heard from you. I think they found that the new superseded part number for the crank sensor required a complete power down of the PCM to relearn the new crank sensor.

There was a similar post going at the same time this post came about.
 
Been CRD'ing exclusively - plus repairs around the ole domicile - the house, too..........

The engine will run off the OS if the CPS is failed\failing without dying - limp mode has no power but does not die repeatedly - the CPS is just a 5v hall-effect device, responds to magnetic flux variations, gives 0-5v squarewave out - if TDCO is within spec, PCM doesn't care what the part number is, long as the input signal is a 5v squarewave - doesn't explain the repeated dying, like losing connection when the block twists due to torque reaction - if they pulled the PCM connectors to accomplish the deed, then some connection was restored during the connector R&R - however, the complaint still indicates intermittent connection, not failed module, nor intermittent fail module - like the Terminator, it'll be back................
 
The only difference in disconnecting the batteries and swapping PCM's is the PCM connectors are removed and replaced, which burnishes the contacts - both procedures dump the driveability parameters, but neither procedure will dump TDCO - however, disconnecting the batteries won't clean the contacts in the PCM connector, for some reason - so, it is my contention that the fat lady ain't yodeled, yet
 
Thanks, my friend - and good to see your turbo experiment is working out -
 
Thanks, I just want everyone else to be as satisfied with the turbo as I have been. Been a long road, have to thank TD for supporting this, others just dismissed it, he had faith :arf: or was just as crazy. Either way we are almost there.

:cheers2:
 
Could a loose timing chain have the same effect. It cranks, and once it fires the slack goes the other direction causing it to shut down?
 
Still trying.

I tried a clear line from filter to IP. No apparent air leak.
I did find a small hole in the tube going up through the center of the filter. I am afraid this may allow fuel to pass through without being filtered. I replaced all o-rings, and fuel line on the return. All others were replaced previously. Installed a small inline filter before the fuel enters the IP untill I can find a replacment filter housing.

Pulled the intake to check the wiring harness. Found one damaged wire on the temp sensor. It had a couple of threads of copper still holding it. Didn't think it had to do with my problem but I repaired it. I had checked resistance from most sensors, ect to the PCM previously.

Pulled the top off of the IP while I was in there. The fuel looked crystal clear in the IP. I vacuumed all of the fuel out of the IP and did the optic bump while I was there.

I cleaned out the intake while it was apart and trimmed some of the aluminum out of the upper intake to improve airflow. There was some carbon build up in the intake from the exhaust feeding through the egr valve.

I removed the pump mounted driver and compared it to the one I had on the intake from SS diesel. The one that was on the truck had a #5 resistor, SS diesels setup came with a # 9 resistor.

I moved the PMD to the nostril of the bumber using a homeade wiring harness.

I unplugged the computer and let it sit a while hoping to have the same results as Mutava.

Put it all back together again and after burping the IP, she cranked and ran a while. I let her room for some time to see if she would do a relearn. After I shut her off, she wouldn't run. She would still crank and die again. I unplugged the OS and she cranked and ran fine...in limp mode. I plugged the OS back in and unplugged the CPS. She ran fine again...in limp mode still. I tried both of the PMD's and still same results.

I went out this afternoon and she cranked up. I drove her for about 45 minutes. When I shut her off, she wouldn't start again unless I unplugged the OS or CPS.

Plan of action: Follow gmctd's advice and check grounds...again.

Test the CPS with and oscilliscope. I hope this will let me know it is getting a good signal and I didn't mess up the gear that the CPS reads from when pulling out the old CPS.

Check both PMD's on a running truck. If they both are bad I will go ahead and purchase a new PMD.

After that, IP?
 
If it was my truck I would be putting it on a scanner about now....gotta see what info the ECM is seeing...
 
You must log in or register to reply here.
Back
Top