• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Lift pump

94DieselSub said:
So about a year ago on one of my summit racing visits, on an impulse bought a Carter P4601HP. My thoughts are yes some have complained about them failing on diesel.

But - years ago I came across a forum (don't know which one) were a member stated he thought his Carter pump failed. He got a freebie warranty replacement, so he opened the 1st one up to find a plugged up SS filter screen on the inlet side. Cleaned it and found the pump was actually fine.

So perhaps those who thought their Carter pumps got noisy & failed, maybe suffered from the condition? Apparently said screen is somewhat easily removed.

The P4601HP is diesel rated, flow-on-fail, 18psi max, 6-9.5psi @ 50gph. Now I installed a large baldwin pre-pump water separator/50u Filter, and a 7u absolute donaldson filter before the DS4. The leaky pos oem FMS got deposited into the round-file!

So when I get around to installing this Carter, I plan on regulating the idle pressure via an adjustable pwm buck voltage regulator. Set point of say 10psi at idle at the discharge port of the 2nd filter. The discharge port of the 2nd filter will also have a 8psi low pressure switch. Said switch will trigger a dc-dc SSR that will bypass the voltage regulator, thus allowing max available lift-pump pressure.

I don't plan to run any more bio than the 10-15% already mixed into pump #2. So I feel somewhat confident that this Carter should last awhile. If and when I get around to installing it.
Click to expand...
 
BTW, I'm currently running a ep158 pump, not terribly happy with it! It hammers my firewall mounted secondary filter like a jackhammer at idle, and goes dead quite ( probably no pressure) at anything past 1/3 throttle.

These shuttle type lift pumps basically fail by design. The only ones that were half way decent were the original oem ac-delco units installed on the assembly line. After that, its all down hill for replacements!
 
@1999gmc,

What is the p/n for that inline delphi pump your running? I assume it is a 14-20psi TBI sys pump, because all the rest of that style are efi pumps that deadhead at >50psi.

That model is a rotory vane type, so technically should be a flow on fail. They are usually relatively chemically resistant too. With a few aftermarket fuel filters to drop pressure a bit, it should make a DS4 quite happy. Now if it has longevity too, its a winner!

I think after being de-screened and voltage speed regulated, the Carter unit I've got should last awhile too.
 
You must log in or register to reply here.
Back
Top