Howdy,

Well, I think you guys were right...the stock lift pump on my truck "just ain't makin' it" anymore.

Last night when I came around the corner by my house the next door neighbors were out in front...so I decided to give 'em a little smoke show (some tire,lot's of diesel)...

Anyway, as I've mentioned before, the truck has developed a miss sometimes after WOT applications...

This time it died.

Couldn't get it to restart at all until I cracked 3 injector lines open and turned 'er over a few times...then it started on those three and continued to run like that (on three) until I drove about halfway down the block.
I also noticed it seemed like one of the injector lines puked a tiny amount of foam when I loosened it.

That sound about right? Lift pump?

What pumps do you guys recomend?

How much? Where?

How hard is a non-stock pump to install? What will I need besides the pump itself to make it happen?

I'm also thinkin' now is a good time to install all new rubber hoses in the fuel system. Any special kind of hose I should use? Regular fuel line OK ? If it is,I'll actually use fuel injection line just because it's tougher...

How about the fuel filler hoses? From the filler neck to the tank...what should I use there?
I gotta figure radiator hose will die in short order when exposed to diesel fuel in that spot...same thing for using heater hose on the vent ...

Well, thanks in advance for any and idea's and advise.

Much appreciated,
Vinny

 

Sounds more like supply lines than lift pump. I just went through the same thing. Similar symptoms---hard start on certain grades. Finally, I got under the truck and pumped the lift pump primer and after the 4th or 5th plunge, I heard the lines start breathing and then I saw the supply line start to weep. Cut out the rusted steel line and patched in some rubber stuff and it runs better than ever. You're definitely getting air to the VE, but be sure to narrow down where it's coming from before you buy parts. With a leak free system, the VE will feed itself with no lift pump, to a point, so air bubbles says corrupted lines. Check 'em first---at least it's a cheap fix if that's it! Someone else will hopefully chime in on what kind of line to use.
greg

 

I had a gauge on before I changed the pump. I was down to 1 PSI at WOT. with a new pump Im holding more than 4 PSI WOT and 6 PSI most of the rest of the time. Not sure about the stalling, I would try a new pump and go from there.
Be carefull not to get too much pressure, rumor has it our injection pumps cant take more than 13 PSI. But I dont know this for a fact.

 

Wannadiesel and a few others I believe have installed the upgraded piston lift pump from cummins. The pump is exactly like the 2nd gen pump however it operates at a lower pressure rated for the VE pump. I believe he said that the pump is running at almost 20psi at idle!!! and doesn't drop much at WOT. I'm sure when he gets on he'll correct me but I would go this route if you really think its your supply pump.

Or you could get an electric pusher pump like I did, however I have no idea what pressure I am at the pump was rated for about 7psi.

 

https://www.dieseltruckresource.com/...ston+lift+pump

 

Vinny-
Do the piston lift pump. It's a little under $200 for all the pieces from Cummins and it's an easy bolt in job. The only "custom" work you have to do is hacking the noise insulation on the tappet cover. It's foam rubber, so it takes about 2 minutes with a sharp utility knife.

I have no idea what my WOT fuel pressure is because I can't find a volunteer to lean over the fender and look at the gauge. Idle pressure looks to be somewhere around 17-18 psi, it's hard to tell with the way the needle bounces plus it's a 15 psi gauge.

If you have the plastic fuel lines (I think they started in '92), leave them be unless you see one that's pinched, chafed, or cracked. They are very trouble free.

 

I went the piston pump route and it is an easy install. PM me if you want the part numbers and the prices.

Bob.

 

Bob, you have a PM

Stan

 

OK about a year ago I was on this Forum and I was told my pump would leak if I get over 13 PSI So are we changing the rules now. Good, I have a second gen pump just waiting for me. Well I will be leaving for Idaho in 3 weeks, If I blow my injection pump on the way there, I will be on forums for some serious discussion
dont take this the wrong way, but you east coast boys (and girls) dont know what its like to see that sign that says " no services 108 miles" that means, there is nothing for 108 miles----and I mean nothing. no cell service--no nothing.
OK with that said Im installing the second gen pump

 

OK so I will have a spare stock lift pump and injection pump, but I sure dont want to change them on the road side

 

It's NOT a 2nd gen lift pump .

Again, It's NOT a 2nd gen lift pump.

Last time I'll say it, It's NOT a 2nd gen lift pump.

If you have a piston lift pump from a 2nd gen, DO NOT install it. It operates at a much higher pressure than this 1st gen piston lift pump. 13-15psi idle vs. 25psi idle. 3-13psi wot vs. 35-50psi wot.

 

Its the same design as the 2nd gen however operates at lower pressure.

I repeat its not the same as a 2nd gen lift pump do not install a 2nd gen lift pump

 

frostie, if you have a 2nd gen pump laying around, get the rebuild kit for the 1st gen piston pump and rebuild it with those parts. All you really need is the weaker spring and you're all set.

 

Also Frostie, if you rebuild that 2nd gen lp with 1st gen piston lp parts, you won't be able to use the new fuel line. You'll have to rig something for the fuel line from pump to filter housing. The two piston pump have different outlet fittings on top of the pump. I compared them at the shop before I did mine. I doubt the hard metal line would line up properly or reach. You might be able to heat it up and stretch it. Or change the fitting?? The fitting on one is shorter, can't remember which one though. Then again, you might not have any problems.

 

When I decided to go to the piston pump I researched the subject in the TDR archives and came up with the following information. Dieseldemon AKA Jim Leonard a well known Diesel technician and "performance enhancer" posted the part numbers for this upgrade. He also stated that these numbers were NOT for a 2nd gen lift pump but were for a replacement for the original 1st gen lift pump. He has done quite a few (100+ if memory servers me) with no problems. He indicated that some of the P/Ns might be superceded - this was the case with the lift pump P/N. I'm listing the P/Ns as I installed them on my '93 and what I paid for them at Cummins NW
1 - Pump, Fuel Transfer P/N#3936320 - $153.23
2 - Gaskets, Cover Plate P/N#3639258 - $1.75ea
1 - Tube, Fuel Supply P/N#3914753 - $28.29
1 - Spacer, Mounting P/N# 3914284 - $10.40
2 - Washers, Sealing P/N# 3963983 - $1.00ea
Total cost $196.42

Hope this helps and clears up some confusion.

Bob