And a Multiple-Split at that.

 

Has anyone tried the 2nd gen piston lift pump with the 1st gen piston lift pump conversion internal spring?

I am having a fuel issue and it might be as simple as a fuel filter but it may be the stock lift pump on its way out.

I was stranded on 696 east of detroit for about an hour trying to get the truck started. I used the manual primer arm to get some fuel back into the engine and it started.

I made it back home and the truck started fine the next morning, but after heading into town it died again.

 

That's exactly what this thread is all about.

I had always heard one could simply swap the 2nd gen spring into the 1st gen pump body.

Based on my findings here, it can't be done as the internal parts are much different (see above images).


kiszka6911, you might check the engine oil level to see if it's mysteriously rising (indicating the lift-pump is leaking diesel internally into the engine oil sump).

Further, you may be having issues with air leaking into the suction side of the lift-pump there-by breaking its prime.

 

Okay I haven't had the pumps apart but but just looking at the pictures, why can't the 1st gen piston pump spring be put in backwards? It appears that it is the correct diameter at the big end. If there is concern about the spring getting cocked in the bore maybe a small stepped spacer could be made to center the small end.

Secondly do you have a local speed shop or maybe you have a valve spring compression guage that we could measure the springs rate for the 1st gen spring and possibly find something close that is the correct diameter?

As for my issues stalling stumbling issues after making to the garage the truck ran fine for an hour parked and idleling, also revved the engine and held at fairly high RPM for 15 seconds with no stumbles.

To me it acts as if there is a blockage in the fuel line or there is some ice in the fuel line that gets sucked up as all the fuel rushed to the back of the tank during a high RPM shift. I am running power service diesel 911 addtive which is supposed to help with water but maybe I need to try something else.

 

I don't understand why one would want to put the OEM spring in backward.

Are you after increased fuel pressure?

Are you after increased fuel volume?

- Or both?

Are you wanting to stick with the piston lift-pump that we've typically gone with (the smaller of the two)?

NOTE ~ Our 1st generation CTD's never came with a piston type lift-pump. Not even as an option. OEM is the diaphragm type pump.

Frankly, I'm not sure where the piston pump we normally would get was sourced from. . . .. ? I don't know how it was selected nor by whom. I wouldn't be surprised if there were a better choice for our application but who knows where to find an actual break-down of the performance characteristics of the lot. To date, I've only been able to find a VERY limited source of fuel lift-pump specs (that being Cummins Fire Service engines).


Anthony, What'cha up to?

 

Well whenever possible I try to minimize my exposure to addtional stuff, in this case an aftermarket fuel pressure regulator.

So if you could put the low pressure spring in the high volumn pump you would most likely be able to continually source second gen pumps as needed and just change the spring.

I would think this would push enough volumn to meet the needs of a healthy VE pumped motor. I would assume the piston pump would have similar performance/rpm range to what you saw just at a lower pressure.

This keeps me being able to buy spares at the local auto parts store without a lot of custom plumbing.

I sourced the aeromotive regulator you used today, which I still might use but its not a cheap item.

 

I found this :


http://www.vulcanperformance.com/ser...06JIC-X/Detail


My understanding is that using this fitting will accomplish the same thing as what you described.


On my truck, not knowing any better, I managed to use a 1/4NPT fitting in the outlet.

The problem with that is the outlet threads are straight metric, whereas the NPT threads are tapered pipe-thread.

The 1/4NPT WILL easily screw into the 14mm metric threads of the outlet, but do not achieve an easy seal as they would in a NPT hole.

I did manage to achieve a leak-free seal, but highly recommend using the proper fitting instead.

 

Yes that is the correct adapter for the pump output. I put an Aeroquip p/n in but I have the steel part reay to go in. This part has an o-ring with a steel collar around it to provide the correct seal. GDP also should have a stainless steel version anytime now.

 

so im guessing the new 1st gen diaphram lift pump i just bought wont support a tweeked pump POD's and a HX40 huh? so should i try n return the diaphram lift pump i got and get a piston pump, and regulator ?

thanks karl

 

Return it and get the 3936320 low pressure piston pump and be done with it. All you'll need to 450rwhp.

 

i've got a pump that was supposed to be a 1st gen pump until i installed my pressure guage (15 psi ) and it pegged at an idle. drove it hard and the guage never moved at all. removed the guage and hooked the line to my oil pressure guage and instant 45 psi.

now the reason i told ya'll that is because on the old bb mopar engines we used to shim the oil pump pressure spring to increase oil pressure and we also would cut coils of the holley secondary spring to get them to open sooner. so my plan is to mount this obvious 2nd gen lift pump and remove the spring and cut of a little at a time until the pressure is were i need it to be.i should be able to achieve 2nd gen volume with 1st gen pressure. i'm reading pressure at the filter outlet. anyone see a problem with my thinking?

daryl

 

Just wondering why you would want to change the pressure of your pump? If 15psi is ideal and you're getting that all the time why change?

gary

 

my pumps getting 45 psi all the time. if i can cut the spring down to 15 i'll be happy

daryl

 

S why not just run the 2nd gen LP without a regulator? What would the pressure be then? I like simple. lol

 

45 psi will blow the shaft seal out of the ve. it will then fill the crankcase with diesel. at least thats what the experts say. mine lived at 45 psi for 2 months before i installed the guage.

i also dont want to run a regulator. just one more thing to fail while i'm in the woods on a camping trip with the wife about 6 hours from home. i like simple too.

daryl