• 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!

Crank no start

snarl95

snarl95

Well-Known Member
Messages
1,025
Reaction score
1,675
Location
Edenton,NC
So Friday I had a fishbite and stall episode. Pulled over truck started fine and ran great rest of the day. Saturday truck starts fine, run some errands and proceed to replace water pump and radiator. I had disconnected the positive cables. Got that all done and now the truck won't start.

New PMD and cable
Gutted fss
Have fuel to ffm,out of air bleed,out of drain and to injection pump
Fuel in clear retun line, moves a little when cranking
Tried cranking with optical sensor unplugged and cps unplugged, no difference
Have SES light when cranking. (power to ecm)
No fuel out injector lines.

Am going to check grounds again and add trans fluid to ffm next.

Any suggestions are greatly appreciated
 
Please DO NOT add trans fluid to FFM.
Trans fluid is not designed to burn clean as fuel anymore.
It has a lot of additive to make it last longer.

Unless you can find a trans fluid made in the 70's time frame but I would not use that either because it is probably already pass their shelf life.

As far as your issue, have you done a load test of the batteries one at a time?

Also, you said new PMD and cable?
Have you test the PMD without the extension cable? to see if it is the extension cable problem.
Is the PMD attached to a heatsink?
 
What is your fuel pressure at the time of the issue? Clear ip return line looks good ? Sounds electrical but anytime fisbite is involved, check the basics.

I run atf (dexron3) but dont use it when you are trying to figure out a problem umless you have already determined the head and rotor in the ip are worn and need the fuel slightly thicker. Many of the mfrs still make it to the same specs they did back then- just not GM approved because they dont get paid rights for it.
 
New pmd
New cable
Tried both without cable
PMD is on heat sink
Cranking speed is good.

No idea on fuel pressure when stall happened.
Fuel in clear line moves a little when cranking. No bubbles.
 
You need to know if fuel is getting to the cylinders now.
Either pull a glow plug or remove an injector line from injector, have someone rank it while you watch. If alone, you need to use a remote starter switch.
 
This should give you enough info to make sure the pmd is getting the signals it should as well as the output
 

Attachments

  • PCM-FSD-IP signals and no start.pdf
    659.9 KB · Views: 20
  • PCM-FSD-IP signals.pdf
    479.8 KB · Views: 13
I'm getting fuel out bleeder, out t-valve, and to the pump but nothing is coming out of pump. I want to eliminate all possibilities before I order a new pump. It would suck to spend the money on a new pump and be in the same situation. I just doesn't seem possible that the pump just stopped working.
 
Is your brand new PMD tested when the truck was running?
Brand new usually good unless it is a Dorman PMD which for some reason has some DOA.

Have you eliminated that it is not the extension harness?
Also, there is a chance that the IP harness is weak or bad?

New parts are not always good/working.
 
I had a harness that tested good for continuity, but one of pins in the harness was not making connection. It lost connection while mybwifecwas driving down the road after being in place for several years. Follow the PMD diagnostics. The IP harness has also been known to go bad. I got to the point that I would just replace the engine and IP harnesses when I worked on an older 6.5 as a matter of routine maintenance. None were in all that great of condition when I replaced them
 
So I guess I'm confused as to what you did. You need to ohm the grounds to make sure they're good and the red wire should read ac voltage going to the fuel selenoid. The black wire going to the fuel selenoid should be a ground as well.
 
Sounds like the first test with the plug unplugged to see what you have going to the PMD.

He should also do ground continuity at this time and test the harness for continuity. I made a harness with a T to test for power coming back from the PMD. I don't like probing wires. I have enough issues without purposely poking holes in wires
 
You must log in or register to reply here.
Back
Top