1fatxl

Can anyone give me some definitive symptoms of a failing lift pump. Truck is a stone stock 96 auto 4x4. Has recently started to have to crank on the starter for a long time to get the truck to light up. 10-15 seconds, and about 3 tries at that. I didn't see the amp gauge on the dash moving when wait to start light was active, so took it in to have the relays tested, and they are shot according to the mech, and also i need a lift pump because it isn't working. They said he couldn't "hear or feel the pump working" . It isn't that i don't trust the dealer. OK it is that i don't trust the dealer, any help out there?
thanks

patdaly

1.) Your 96 has a MECHANICAL lift pump on the side of teh engine, you will not hear it run.
2.) the Heater relays are about 60 bucks from RockAuto.com, do it yourself and save a bunch.

3.) Your starting problem is likely a leaking or cracked fuel line, simple way to check is to pump up the system with the lift pump primer button, probably 250 or so pumps, use a garden implement handle, makes it easy to pump. If it fires right up, you have a leak in the system somewhere, which is quite common.

If you give it just a little bit of throttle, does it fire off right away?

1fatxl

Yes, if i give the pedal a little bit it will fire, but let it off and she quits. takes 2-3 tries before it will idle.

Now this morning i noticed the grids pull a little, and she started easier. I am thinking the guy messing with it might have re set the wires, and maybe it needs to have contacts cleaned.
Also I have no other probs with the truck, runs like a champ once started.

Fueling around

Try bumping up your idle. Cooler temps is when the diesel isn't so friendly.

Dartmouth 12V

As stated above, you probably have an air leak in the fuel system. Does the truck get harder to start the longer it sits? Have you ever replaced your fuel lines and is the fuel heater still active?

The other possible problem is a really low idle. You should be seeing 850 when warmed up in drive with the ac on.

caburnside

I have been having the same problem. But mine didn't start until after I replaced the lift pump. I just think it is to ironic that my lines would get a leak directly after replacing the lift pump. I find myself priming the pump every morning and sometimes throughout the day now, it is getting annoying.

Fueling around

I had a latent air leak after replacing the fuel heater. It didn't show up unitl the temps warmed a couple months later. The top seal rolled slightly. It took a long time to find that problem.

With any problems, start with the basics. It is often something very simple.

caburnside

I did a basic bleed by loosening the bleed bolt and priming the pump until all bubbles were out, did that twice but no luck. I then bled from the lines and no fix. I thought I had fixed it because the next morning she cranked right up but it was back to normal the following morning. I am going to have a friend whose a diesel tech look at it and diagnose it while I am having him replace my head gasket later this week hopefully because I am stumped

Over all not the biggest pain in the world. I mean at least she will always start even if I am having to prime the pump first, LoL,

infidel

By far the most common starting problem is the return hose in red below sucking air.
It can suck air without leaking fuel.
Replace it and the feed line next to it while the head is off.

GAmes

The same thing happened to me. There is a small grommet that fits under the nut on the inlet side of the preheater/filter fuel line. A word of warning, if the Cummins place doesn't have one, do not order it overnight shipping. That $4.50 part cost me $60. It was overnighted from the manufacture to the warehouse, again to the Cummins place in Ft. Worth, and they overnighted it to me. Took 6 days. If I can find the part# I'll edit this later.

caburnside

That'd be great, I am dropping the truck off at my techs house tomorrow and plan on stopping by the Cummins house in Mesquite on the way to pick up the head gasket and the things you guys have mentioned if they have them. I have no doubt he can look at it and diagnose it in about a minute but would rather have all parts possible in hand so as to not slow up the favor of a job

GAmes

It is a grommet, part # 3923194. Here's a pic. One other thing, it is shown as a sub-assy of the fuel line in the Cummins system. Dodge (of course) has no idea what it is and it doesn't show up in the fuel system blow up, but the fuel line does.

caburnside

Would figure Dodge would no nothing about it, LoL, thanks a ton for the info I will be picking these parts up tomorrow for sure from the Cummins house (unless I have to overnight, of course)

caburnside

Thanks for the info I will be sure to replace those as well, might as do them now and not have to worry about them later.

1fatxl

AOK, I am guessing i have a leaky fuel line somewheres. But my question was are there any "classic" symptoms of a failed lift pump? Having some "mechanic" tell me its bad without really testing makes me wonder, especially since I can come here and find out that it is incorrect rather quickly with the people and experiences available.
So, Is there an A-B-C of things that point out that the llift pump is bad?