My lift pump story. (long)

[Amianthus]

Here's my lift pump story.



I've been running on the same lift pump for 50 kmi. I never thought there were any problems. But recently, I developed a bad stumble. It became more pronounced after I installed my Super-Mental injectors. Now it couldn't be fuel, because I still had 11 psi at idle and 8 psi (no box) WOT. So I went searching. APPS? Too expensive. CPS? No, that checked out. IAT, MAP, APPS (eventaully) all checked out fine. Could it be the VP-44? I hoped not.



I was convinced that it wasn't the lift pump because I still had the right amount of pressure (mechanical gauge calibrated at work). But I thought that a pusher pump might be a good idea because I could starve the pump with the box on. So I ordered a Summit Pump (part # SUM-G3134) 15 psi 140 gph. Thinking this would be a superior pusher pump. I was gonna install a check valve in parallel with each pump so that if either one failed, the other would be able to continue to work automatically. Thought I was pretty smart.



The next day my pump started mis-behaving. Can you believe it? What carma. I videoed the gauge behavior so that those of you who don't know what to look for, can see what a failing lift pump does.



Video 1. This is during the startup. Pumps running, no pressure.

Movie 2. This is idling in the driveway.

Video 3. This is going down the highway at 65 mph.



As soon as I got to work, I called my dealer to let them know that my lift pump was going bad. Now I have an awesome dealer. They called me back a little later and said they had the new pump on hand and could install it whenever. I got it done. I told them I wanted to analyze the old pump once it cleared warranty. After a couple of days, they gave me my old pump.



I drove it home at 14 psi and 8 psi WOT. It was like driving a new truck. I had all that power back. But I had the pusher pump, so I might as well install it to help the new lift pump live longer, right?



I installed the pusher pump. I tapped into the new jumper piece that came with the new lift pump to power the pusher pump. I mounted the pusher to the frame rail just ahead of the t-case support. Started the truck and... HOLY COW!!! Over 30 psi . Turned down the reg as far as I could. I knew this was bad. I finally got it down to 27 psi. Still too much. What do I do without spending a ton of cash? Regulator? Bypass original pump? Run original pump until it dies then put in pusher?



I finally decided to retire the stock lift pump in place. I took the old wiring harness of the original lift pump and mated it to the new pusher pump. I then re-worked the plumbing so that the pusher pump flows right into the filter. I took the line from the original lift pump, cut it on half, installed a piece of flexible hose inbetween the halves (so I could bend it) and used it to cover both ports on the old lift pump. I also took off the old electrical adapter piece and put it in the truck box. This way, if the pusher pump fails for some reason, I can put the "new" lift pump on line in short time so that I can still drive the truck. I hope I never find out.



I started the truck, readjusted the regulator to 16 psi and drove on down the road. No more stumble, and plenty of fuel to spare.

That's my solution to this problem (for now). What a way to fix a problem I didn't think I had to start with.

 

[Pit Bull]

Very interesting, please keep us posted.

Thanks

 

[MCummings]

Ditto.



I just put dual pumps on mine.



Where did you get your 0-30 gauge? I need one bad.



Thanks,

Merrick Cummings Jr



EDIT: I liked the videos. You got anymore cool ones?

 

[duaneparks]

Originally posted by MCummings

Where did you get your 0-30 gauge? I need one bad.

I was wondering the same thing, then I noticed his is an Isspro Manifold Pressure gauge.



Cool. I had asked Isspro about making a FP gauge like that, but they weren't going to at the time. So, I'll be ordering the Manifold Pressure gauge to do the same thing I reckon.

 

[MCummings]

Originally posted by duaneparks

So, I'll be ordering the Manifold Pressure gauge to do the same thing I reckon.

Well Young 'un, I reckon I'll be doin' tha same thing,,.

 

[Amianthus]

Yup. That's what it is. It's my old boost gauge. I had it laying around so I thought I'd use it. That, and I am a huge fan of mechanical gauges. I used a copper gauge kit to install it and I ran it through a tube that drains outside the cab. That way if I have a failure, it will drain outside the cab. The air pocket in the line acts as a buffer against pulses so that the gauge is somewhat readable. What else do you want to know about it?

 

[duaneparks]

Originally posted by MCummings





Well Young 'un, I reckon I'll be doin' tha same thing,,.

LMAO! Ah b'lieve mah Tennessee roots are showin'!



That is a cool setup. When I'm ready to install mine, I'll give you a shout and see if I can't get more info. Thanks Amianthus.



Duane

 

[Amianthus]

The safest way to use a mechanical gauge is to use an isolator. You can get them from Summit, Jegs, etc. I'm just too cheap and had the parts laying around.



I like mechanical gauges because of reliability, durability, and readability. But that's just me.

 

[tmacc]

A,

I just got my Summit pump today. Do you think that a regulator is needed? When I querried HVAC about a pre-filter, he posted that he didn't use a pre-filter and that the Summit pump was internally bypassed and he wasn't using a regulator either. Of course, I don't have near the HP he does. TIA

Tom

 

[Amianthus]

The Summit pump listed above has an intergral adjustable regulator that is set at the factory to 15 psi. I don't use a filter on the inlet either. I don't think it's necessary. I don't see anything preventing it, I just don't think that I need one. Still working great. But it's only been a couple of days.

 

[tmacc]

Thanks for the info. It's going in this weekend.

Tom

 

[EricBu12]

Animanthus,



I did put a pusher pump in line with a carter 15 psi pump and wired it up like you did but my pusher is a 7 pound 100 gph pump and now I have a electric gauge pre filter and it shows 15 psi on bump prime but 13-14 idle, 11-12 cruise, and no less than 8 WOT.



Here is the pushe install with a prefilter with a aux fuel heater and Water in fuel sensor and filter minder (last 2 goes to 2 led buzzers in dash to alert me)



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