Engine/Transmission (1994 - 1998) Engine dies out

[Kalaehina]

Ok here's the scenario-96 sitting for about 3 years, started once a week, ran every time no issues. Last week took truck out to get road legal again, drove for 20 miles no problems, get home truck starts to run rough, idle drops, truck dies. Before I ran it on the road last week I dropped the fuel tank, drained it, cleaned it out, changed the fuel filter (again today so that's twice). Truck will start, idle but occasionally run rough, I had it idling for 20 minutes today, drove around the neighborhood, came back idled fro another 10 minutes no problems. Start up 30 minutes later, rough again and dies out. Any ideas? Lift pump? Air in lines?

 

[crabman]

Read the attached link & follow the instructions. This will help you eliminate the FSS as the problem.
http://www.cumminsforum.com/forum/94-98-engine/569868-fuel-shut-off-solenoid-fss.html
This link is the best (IMO) article on dodge diesel fuel.
http://www.cumminsforum.com/forum/94-98-engine/58777-joe-gs-fuel-system-writeup.html
I bookmarked both of these & also printed them out to keep in my files.

 

[Kalaehina]

Thanks! *I'll go check it out!

 

[Missouri Mule]

Unfotunatley your engine keeps on dying or you could take fuel pressure test.*
Did you fuel it up when you took it out for 20 mile run? Could of got bad fuel( water/dirt...).
I doubt it is air. If it was be hard to start.
Could be your overflow valve. I had the metal ball get stuck in passage way from p7100 and overflow/fuel return line. If there is to much pressure the p7100 will shut down.
Also and more likely the overflow spring can get weak and let fuel of out p7100 at lower pressure then it supposed to. *Which I believe will cause rough running and eventualy dying. I will look at my fsm to see if those are the correct symptoms, if the fsm. Did not see any sympton.
How much fuel do have in tank? If tank is low and for some reason your cap pressure is not correct ( to low) that will make your engine run rough. Don't know about dying. *Several years ago member bought truck with locking cap and did not have key. Got cap off but broke it. Filled up, went down road. When fuel got down about half tank started to run rough. New fuel cap and fill up he was able to make home. He drove 2 days to get home.9

 

[Kalaehina]

I pretty much had full tank of fuel. *Could dirty prefilter/heater do that? *I do have a new overflow valve coming just to be sure. *

 

[Missouri Mule]

If your pre filter /heater screen was clogged you would have starting problems. Sometimes the wire going into the heater/filter melts and lets air in but that would give a hard to start situation.
If the fuel was in their for a while you could have water or algae in it.
Use your fuel drain. Drain fuel in to clear container and see what the fuel looks like. If it has water in it the fuel will have what looks like air bubbles but is actually water.

 

[Kalaehina]

Ok prefilter was a little dirty but yes I don't think enough to kill the engine. *Going to replace the overflow valve tomorrow and see what happens. *Thanks!

 

[Kalaehina]

I also drained out fuel from the filter, everything was clean and clear

 

[Kalaehina]

Truck will not start now, cranks but doesn't start. *Opened bleed screw, primed, fuel only came out once and nothing after that, although I'm continuously pressing the prime button. *Fuel is also not coming out of the injector lines when I opened them to try and bleed air out. *Lift pump? *Air getting in heater? *I plan to remove the heater tomorrow just to eliminate that possibility, and I'm in Hawaii so I don't really think I need it anyway.

 

[crabman]

Air leak or bad fuel pump. The second link in post #2 will tell you how to check the fuel pump.*Quick Lift Pump Test

 

[Kalaehina]

Would that lift pump check still apply if I can't get the truck to fire up? *

 

[crabman]

"Opened bleed screw, primed, fuel only came out once and nothing after that, although I'm continuously pressing the prime button. "
If you disconnect the hose that goes from prefilter/heater to pump and attach another hose from the pump to a bucket with fuel in it. Open bleed screw and press the prime button, you should get fuel out of the bleed hole. It might take a few pumps as the hose from the bucket to the pump has air in it. If you get a continuous flow of fuel, close the screw and your truck should start. NO fuel out of bleed means bad pump. If truck runs, then you have a bad air leak before pump.

 

[Kalaehina]

Has anyone ever had a pre filter screen bowl just be absolutely stuck? *Like so stuck I have to get an extractor for rounded bolt head. *What's more strange is that I just removed it last week no problems, now today it just won't budge??

 

[Missouri Mule]

The lift pump is two in one the primer button mite work but not the part where it supplies fuel to the p7100.
There are check valves( do not let fuel go back toward the tank) in the pump that can fail. I believe there is at least 2 maybe 3 in the main part of the pump and one in the primer part of pump.

Twice have had starting problems, once when Mule had 20,000, I had it at Dodge. They sent to Cummins . Cummins put new p7100 on it . That did not fix it. They sent it to a well know shop down the road they replaced the fuel return hose. That got it starting again. I always could get engine to fire up if I primed it. That was in 96 in 2000 it started to do the same thing I put a neapreme (spelling?) hose on Mule. Still on no problems. That said I had the lift pump and overflow valve replaced with in 4 weeks of each other. Was getting close to 300,000 on Mule.

 

[DonFitzwater]

Sounds like it's time for a lift pump and heater delete. You can either grind the mount plate section of the heater mount to use as a spacer or order one from Genos garage. The new lift pumps from Geno's come with studs now for easy mounting (the two bolts from the factory suck). You'll really want to check the plumbing between the tank and engine for rubbing as holes can develop.

 

[GAmes]

The heater unbolts from the housing, then the prefilter can be reinstalled. No need to grind anything or buy a spacer.

Rubber hoses can suck air in but not have fuel leak out. I suggest you replace the rubber fuel lines including the L shaped one from the prefilter to the pump before spending money on a new lift pump. The L shaped hose is one of the few things you can get from a dealer that doesn't require a mortgage. If you end up with a new lift pump don't overlook the square cut seal that goes into the top of the prefilter housing (the 6th picture in the linked Joe G writeup).

 

[Missouri Mule]

Just off the wall question is your fuel shut off solenoid rod going all the way up when you crank engine. If the solenoid was starting to go it could cause rough running then die.
Also if fuel shut off solenoid died and you were cranking the engine no fuel would be entering p7100 so no fuel would be going to injectors.
Pull the starter relay ( you will need solid wire/wire you use in the house, trim it so you have bare wire on both ends, wire only needs about 4 inches long. ). Put one end into (TOUCH) female terminal near
the battery (make sure your not putting it in where there is no relay which next to fender. Touch the female terminal opposite of the one by the battery. This should turn the starter and pull up the rod to the fuel shut of solenoid (keep a eye on the rod, Engine won't start unless key is in run position. You can leave the key in your pocket.