Morning all,

I have a 1996 2500 5.9L Cummins. The truck ran fine and was sitting for the last week in the 100-degree heat.

Wife went out to start it yesterday morning and it cranks fine, fires, and runs for a second or two, no more, and then shuts down. The problem repeats every time you try and start it. It does not matter what you do with the gas pedal. Has a full tank of fuel.

Anyone have some ideas on what to look for? Also working on really slim diesel knowledge here . Thanks

 

First thing, on the side of the injection pump will be the fuel control lever, pulled in by the big solenoid. It pulls the lever up to start. That solenoid is controlled by 2 separate circuits, pull and hold. It almost sounds like the hold circuit is not functioning. Do a search here on pull and hold and you should find the circuit. I believe it is also in user Infidels photo gallery.

To verify this diagnosis you can simply wire the lever up and start the truck, it will run until you let the lever shut.

 

That is unusally for a 12V. Verify the fuel on/off solinoid is working. Drivers side of engine. Its a plugger looking thing. Its operated by a relay on the fire wall. My Sons (my old truck) did that some time ago and it was the relay.

If thats working, disconnect the fuel line at the pump and crank the engine. If no fuel, the mechanical fuel pump may have split the diaphram. I really don't think its the fuel injection pump as they are good almost forever. Check the fuel filter as well. I don't think its that.

Oh Yea, Welcome to the Forum !

Here's a link to a few threads on the subject

https://www.dieseltruckresource.com/...Firewall+Relay

https://www.dieseltruckresource.com/...Firewall+Relay

https://www.dieseltruckresource.com/...Firewall+Relay

 

Dave,

All good information except a little off on the mechanical fuel lift pump style.

First Gen 89-93 did have a diaphram style lift pump with the VE injection pump.

Second Gen 94-89 had a piston style lift pump with the P-7100 injection pump.

 

Sorry, my 96 had a mechanical fuel pump. It was not electric so it had to be mechanical.

 

Any more info to post yet, did she start with the lever up?

 

Yes all 96's had a mechanical pump and they were a piston style of mechanical pump not a diaphram.

Everything from 94-98 was the same.

The reason why the 1st Gen guys will sometimes upgrade to these is they are a better more reliable pump and they flow more fuel than the diaphram type.

 

Mike have you got it running yet ??????????

 

 

Mike said it fired briefly then died- sounds like air in the lines or lift line (from tank to lift pump), bad lift pump, bad line from lift pump to injector pump (post lift pump you should be having noticeable fuel leaking).
If the solinoid is failing to hold it sounds like a broken connection for the hold circuit where the vibration breaks the circuit- easy to check tho. After trying to start it do not turn the key off and check the position of the solinoid. If it is held up it should be good.

 

I went out today and cleaned up the solenoid connections at the battery. It did the same thing. One of the guys said to push up on the lift pump while starting, it fired right up. Drove it around all day today with out an issue, I'll see how it does tomorrow...maybe it was just simply stuck.....

 

Mike, the solenoid does get gunked up from time to time, the boot rots and garbage gets in. Foster truck sells just the boot, remove solenoid, clean up, install new boot and many times you are good to go.

 

You might have to stay after it awhile. I had an intermittent no-start problem for a while before I got it to quit. Went through it all, blue wire, battery connections, solenoid, starter, ground connections. It's all good now, we'll see how it is when winter gets here.

 

BINGO!! The boot melted all around the spring. Removed the solenoid, cleaned everything and she fired right up. I'll order the new boot from Foster. Thanks for all the direction guys.