My 1996 2500 cummins truck was having intermittent starting issues and now won't start at all. Has plenty of battery power, turns over hard and has fuel. I was told it is the "fuel pump inside the fuel tank" but upon looking online to buy a "fuel pump", I found that there is one just before the injectors AND there is a "fuel module" INSIDE the fuel tank.

How do I know which one went out? Also, assuming it is the "fuel module" inside the fuel tank, where can I buy one besides the dealership? I was only able to successfully find out where I can buy an aftermarket fuel/lift pump which is found near the engine.

Thanks in advance for any help!

Jen

 

First thing to do is make sure your fuel shut down solenoid is operating correctly. Sits towards the rear of the injector pump on top, plunger moves up when you hit the starter and stays up (2 circuits) with key on. After a bump of the starter with key left ON, plunger should be all the way up. If not pull it up and see if it stays. If it doesn't, tie it up with a piece of wire/tie wrap etc and try starting.

Next I would try operating the lift pump primer button until you hear fuel flowing through the overflow valve, sounds like hissing. A broom handle is great for reaching the button. If it starts easier after this, pump is losing its prime. Could be fuel supply/return lines or overflow valve.

Also there is no in tank pump, just the mechanical lift pump on the block above the starter.

You may also have a clogged filter or bad overflow valve, although they usually do at least start.

 

Jen, the only fuel pump(s) you have on a 12 valve is the lift pump on the side of the block, drivers side, middleish, and your Injection pump on the timing cover. There is nothing at all inside the module except a hose going down to the fuel sock.

That being said, as has been suggested, check your fuel shutoff lever first, that is 99 percent of the issues these things have, the boot covering the solenoid plunger rots off and the thing gets gunked up, or I have seen the heim joint rust solid on the end and keep it from moving.

Make sure the lever moves up and down freely, then try and start it.

 

Thank you everyone. I will troubleshoot it this weekend. I really appreciate all your advice.

 

May I suggest also checking the fuel Lines from the tank to pump. They are defiantly subject to rot and upon disturbance of the tank they may have split leaving a micro fracture that would pull air into the system thus leaving the truck dead in the water. A generally replace these and have done custom 316 stainless inserts to the units to counter act this ongoing issue.

 

The mechanic I hired was wrong....it wasn't the fuel pump. Heck, there isn't even a fuel pump inside the fuel tank like he suggested in the diesel model, like there is in the gas engine model (per JoeG's write-up). It was my fuel shutoff solenoid. Well that should be an easy fix. :-) Thanks everyone. I learned SO MUCH about this truck through this process.

 

Cool!

Now don't just automatically replace it, check out Larry B's replacement parts, most always the rubber boot rots off and gunk and grit get up in the bore preventing it moving.

Take it off, clean the bore, lightly oil, put a new boot on, and you are probably golden, about 10-12 bucks the last time I knew.......

 

Yes, thank you. I had ordered that boot online yesterday, and the relay. The solenoid fell apart in pieces (the rod/arm, or whatever it's called, came off entirely) and I think I have it put back correctly (I found no info online so far on how to do it but it seemed self-explanatory by just looking at the parts). I will also bench test the solenoid, and relay, just to see if either are bad and so that I know how to do it. I need to find the instructions on how to test the relay (once removed using the prongs). I tried testing the old relay while installed by removing the 3-pin connector but I didn't get any reading on the red 12v; maybe I am doing something wrong because I am new at this. I also sure would love to know how to test the fusible link by itself, aside from process of elimination...Of course, if the testing of the solenoid and relay pass and then the solenoid doesn't work when trying to start the truck, one might assume it's the fusible link but I want to know how to test it on its own. Knowledge is power. I looked at a lot of articles on this issue but I can't seem to find instructions on how to test the fusible link by itself. Any chance you know how? I read somewhere that if the solenoid doesn't go "on" when trying to start, but it turns "off" when turning the key off, that's a good indicator the fusible link it corroded somewhere. I still need to find that sucker...either it's not blue on my truck because it's already been replaced, or my truck is filthy under the hood. Anyhow, lots to learn and I'm loving it. Knowledge is power. I'm a CPA during the day, and a wannabe mechanic after-hours....in the dark...holding a flashlight.