Archived fuel pump? Truck will not start.

[raxley]

I've recently replaced the fuel lines going from the frame to the engine. This was probably 20-40 miles ago. I replaced the fuel filter just before that. I've had power problems for the last 1000 or more miles. It has had power problems for months, but it has slowly gotten worse. It ran like it only had part throttle, but would get up to 60-70 no problem, but the acceleration was very slow. I've ordered the transparent line and remote line so that I can mount my (already arrived) fuel gauge (everything comes from LarryB) in the cab so I can fix my fuel problems, this was the plan. Probably the 2 items will arrive today or tomorrow. The transparent line goes between the filter and P7100, I believe, and it's to see if there are bubbles in the fuel while cranking and running. Right now I can mount the gauge on top of the fuel filter, and that is what I'm going to be doing after this post.
My truck won't start now. It ran fine (but with the usual lack of power) after the fuel line replacement. Unless I have a clogged line, I'm thinking that this must be the fuel pump. A pleasant surprise is that Napa is only wanting $45 for a new/rebuilt lift pump. It will get here in about 2 hours (unless a friend drives me to the warehouse)
When I try to start it, it cranks and it tries to 'catch', briefly running for a second but immediately dies. I've got diesel in the tank. There is no spilled diesel on the ground.
I will now put on the gauge, am I not supposed to have about 30 lbs. of fuel pressure while trying to start it?

 

[raxley]

Gauge shows fuel pressure only goes up to 11 lbs, so I bought a lift pump for $147. It looks like they changed the prime button, it's bigger than the OEM one.

 

[raxley]

I broke the metal line going from the fuel pump to the fuel filter. Cummin's has another, I should get it tomorrow and pick it up. Is there any 'work around' (like using flexible line?) for this? Or is the metal line the best solution?

 

[Bob4x4]

Is this a 94 ?

 

[BigPapa]

Is this a 94 ?

Yes, I believe this is the '94 in his sig.



Have you checked the OFV? Use a pair of vise grips, with a heavy rag or something else in the jaws to keep from damaging the hose, to pinch the return hose and see what the pressure goes to. If it goes up, you can pull the OFV, take it apart and stretch the spring out to @ 1/2" long. This should get you by long enough to get you a new OFV. I'd go with a factory one instead of one of the new adjustable orifice types.

Also, make sure your fuel solenoid is pulling all the way up. Bump the starter and leave the key on. The solenoid should be up. See if you can push it up any more.

 

[raxley]

Yes it is a '94.
Thank you for the replies. I will put the new pump in and if it doesn't work, I will try the vise grip trick. I'm not familiar with the selenoid either. I will try that too. Do the lift pumps not go out as much as the OFV and the selenoids? Although when I push on the lift pump plunger, it seems to work, I'm inclined to put the new one on anyway. Does the low power which got steadily worse sound like the OFV? I'm held up right now with that line I broke.

 

[BigPapa]

The difference between a good mechanic and a parts swapper is the ability to DIAGNOSE and issue. Always do what's simple and cheap to diagnose a problem before throwing parts at it. I would suggest checking what I mentioned before going with the new pump. Both checks are simple and cost you nothing. My engine has 500K on it and I have replaced the lift pump once at @ 200K miles, and it was probably not necessary.

The solenoid is shown below. It is connected to the lever that allows fuel into the injection pump. It has two coils in it. One pulls it up when the starter is engaged and the other holds it up when the key is on. If you do not bump the starter it will not pull up.

The OFV is nothing more than a banjo bolt with a spring and ball inside. It regulates the fuel pressure to the pump. The spring gets "tired" over time allowing the fuel pressure to drop.

Either issue could be the cause of your increasing power loss as both conditions will get worse over time.

 

[MLee]

Raxley;
Have you cleaned the PREfilter screen? that might also be part of the problem, of lost power cause your not getting enough fuel through It. It attaches to the bottom of the fuel heater. Just be prepared for a dousing of fuel, use a bag to control fuel running down your arm.

 

[raxley]

Thanks for all the help, everybody. I should be getting a new fuel line in a couple of hours. I'll put the older pump on and do the vise grip 'trick' and stretch the OFV spring if the pressure goes up to 25 lbs (or there abouts) I will also check to make sure that the selenoid is up. I pulled a 'rag' out of that area yesterday, which turned out to be the old boot going around the lower part of the selenoid. Diesel from my fuel leak had evidently melted it. As for the prefilter/fuel heater, I had planned to omit it. I'll cut off the assembly, while keeping the part that goes in between the prefilter/heater. I'm going to adapt the fuel line going in to the filter to go directly to the fuel pump. I live in a very mild climate, I will never need the anti wax properties.

 

[raxley]

I'm looking at the picture posted above. On my truck, there is nothing attached to the solenoid underneath it, but there is a hole (about 1/2" or 5/8") that goes up inside the solenoid. I can see that something was recently attached there by it being clean by the hole when everything else is dirty. I can see, I think, the plunger that came out of the solenoid, it's attached to the linkage. It looks like it has a adjusting nut on the rod that attaches to the linkage. I don't see how it fell out, because it doesn't see to be at the right angle to go back in. I assume that maybe it fell out while I was driving and the linkage was in a different spot so that the plunger could fall out.
Can I wire the linkage up so that it will start, and then open the hood and unwire it and pull it down to turn off the engine?
Is this something that can be repaired, or does this require a new solenoid?

 

[CRodi]

The plunger on my nephew's 95 disintegrated, so it's not that unusual.

Go ahead and wire the linkage and then release it when you want to stop the engine. People do it all the time to get themselves home when the solenoid fails.

It looks like your solenoid is beyond repair. I see you're familiar with Larry B's. They sell a kit that comes with a heavy duty solenoid, relay and fusible link or you can buy the parts individually.

Good luck with your repairs.

 

[raxley]

I'm having the hardest time getting the fuel pump back in, specifically the plunger and spring. When I took out the lift pump, the plunger was sitting halfway out of the hole. I noticed that the plunger side with the hole in it goes toward the cam, and the spring of course goes around it. It seems you cannot get it in wrong, but I read another thread where somebody dropped one in there. I can get the plunger in there fine, I have a strong magnet, and it seems like it's in the right place, at a 45 degree angle (same as the lift pump goes in there). But it doesn't seem to want to let me put the spring in afterwards, and I get a real unsure feeling when the plunger is 'bobbing' around in there (and the spring isn't going in) I don't want to drop it.
Does anybody remember the last time that they put a lift pump in, the best way to do it? Is it supposed to go in with the spring around it, or (it seems this way) do you put the plunger in and then slide the spring in around it?

 

[raxley]

Any pictures? I can't find any in the shop manual I have on CD.

 

[BigPapa]

I'm having the hardest time getting the fuel pump back in......

Hate to say it, but I told you. The issue was the solenoid. I would not have replaced the pump.

The boot could have been "gumming up the works" not allowing the solenoid to pull up fully. My solenoid, the original from '95 by the way, hasn't had a boot on it for years and a few hundred thousand miles. With the solenoid bolted in place and connected to the lever properly, the plunger cannot come out. I would check the lever and make sure the woodruff key is still there. Sounds like it may be gone allowing the lever to travel too far and the plunger to fall out. The key is VERY small and easy to lose so be careful you don't drop it when you pull the lever off. If the key is gone, that could also be the main issue. Without it there the lever to shaft contact is relying on the clamping ability of the bolt which is not enough to keep it from turning on the shaft. If it's gone you'll probably need to get a new one from Cummins or a pump shop.

Now, the lift pump. The pump "lobe" on the cam is more of an eccentric than a lobe. I would suggest getting someone to crank the engine over until you feel the lowest point. You could probably use a dial caliper if it would make you feel better. I would recommend getting a couple of studs and nuts to go in place of the bolts holding the pump to the case. Those two things should allow you to get it on. I don't remember any spring associated with the pump push rod. Here's a cutaway drawing from Joe G's write-up of the fuel pump and cam that might help you.

Good luck.

 

[Bob4x4]

Iirc tic will let the pump install easier

 

[raxley]

Well, I got the lift pump in ok (that picture was a life saver, I was trying to put parts into a place where they didn't belong) but I got the wrong fuel line from Cummins. I needed a line from the lift pump to the fuel filter, I got a line from the injection pump to the fuel filter.

 

[BigPapa]

Glad you got it on.

I got the wrong fuel line from Cummins. I needed a line from the lift pump to the fuel filter, I got a line from the injection pump to the fuel filter.

Get me your ESN and I'll get you a part number.

 

[raxley]

Hi BigPapa,
What is a ESN? I did get a part no. from Cummins, although it was too late to order for the day, it is 1306404. I will call them first thing Monday and order the correct part. Apparently it is only (IIRC) a $32 part. It's just the time that it puts me out of service. Actually it's no big deal as I have a bicycle that's 'running' that will get me through tomorrow, although I'll lose some work hours Sunday, but it can't be helped. I'm just glad that I'm sure that it's the selenoid, and that I can keep it running (after the fuel line arrives). I'll get some much needed exercise tomorrow, and by Tuesday I should have the fuel line. Or maybe Wednesday.

 

[BigPapa]

Engine Serial Number. It's on the data plate on the side of the gear case on the front of the engine.

Did you check the key on the fuel shutoff lever?

 

[raxley]

I didn't check it yet, but I found the parts of the solenoid. I was trying to put in back in where the fuel pump goes, that's why your picture saved my life. I couldn't figure out HOW those extra parts went in there.