5.9 cummins question

[colbystephens]

ok so i'm helping these people out with their old school bus and here's their problem - i don't know the answer. anyone got any ideas?

it's a 1988 cummins C6 5.9. the
problem we are having is that it wont restart after
the engine is warm. starts great when cold, runs great
till you turn it off. then it wont restart.
i have a work order from last december that says the
bus had the same problem back then and that they
repalced the "start and fule shut off solinoid".

everything i ever hear about diesels makes me think this should be the other way around.

 

[tRustyK5]

Solenoid heats up and then stops working...happens to 6.2's as well.

Rene

 

[colbystephens]

hmmm. sounds like i need a shop manual and a new solenoid.

 

[colbystephens]

so is that a solenoid problem or does the heat need redirection?

 

[colbystephens]

all i know about that quote is what was emailed to me. hmmm. can you elaborate a bit more? i don't really understand your post.

 

[CrewCab59]

Not knowing what engine he has ,if it's a 5.9 B" I would check that fuel shutoff,just pull up the plunger ,wire up and test .Those go bad from time to time.

CrewCab59

 

[colbystephens]

ok, so as it turns out i have new info about their engine, which is not a 5.9 as they had originally told me. it's a 6 cylinder 8.3.

the guys at cummins said that for some reason the
piston to the solonoid on the starter isn't getting
enough juice when the engine is hot to shove it in and
allow the fuel to flow. you can manualy push it in,
and then start it, but i would like to find out what
is causing it.

anyone have anythoughts about how to fix this?

 

[colbystephens]

well, i just reread what they wrote to me, and i think i might need more info from them - i don't think a starter would have a piston in it which allowed fuel to flow. he must be referring to the fuel solenoid, not the starter.

 

[CrewCab59]

well, i just reread what they wrote to me, and i think i might need more info from them - i don't think a starter would have a piston in it which allowed fuel to flow. he must be referring to the fuel solenoid, not the starter.

Not the starter!
Try the fuel solenoid .You can just pull up the plunger and try to start it ,if it starts then its a fuel solenoid. (check for power and grounds)

CrewCab59

 

[colbystephens]

yeah, that's what cummins told them. it works to pull the plunger up and start it, but he wants the problem fixed. does this mean replacing the solenoid?

 

[CrewCab59]

yeah, that's what cummins told them. it works to pull the plunger up and start it, but he wants the problem fixed. does this mean replacing the solenoid?

As long as you have your power and grounds, Yes replace the solenoid!

CrewCab59

 

[colbystephens]

i wish i didn't suck w/ electrical stuff. can someone walk me thru checking the ground? i think it has power since it works when the engine is cold.

 

[79k20350]

clean up the ground, to make sure its a good connection. OR if you have a tester you can do a continuity test.