Engine/Transmission (1998.5 - 2002) 2002 Ram lift pump

[JDoiron]

Question, Has anyone installed a lift pump on the frame closer to the fuel tank and left the stock lift pump in place for fuel to pass thru???

 

[gtwitch]

JD, my experience with the st0ck Carter pumps is when they start to fail they are coming apart and the rotary vanes are starting to wear and get loose in the hub and this is producing metal and this goes into the fuel filter (hopefully) I would take the stock pump off and either get rid of it or put it under the seat for a road repair. If this is done correctly, the pump can be replaced with a straight piece of brass tube stock between the two banjo fittings and a relay put on that plate that gets its signal power from the wire driving the stock pump and then fused power from the relay to the new frame mounted pump. I also put a NAPA fuel filter body and filter on the frame on the output of the pump, so mu fuel is filtered twice before the VP-44. All seems to work great for me!

gtwitch in wyoming

 

[Larry Willard]

Many of us in the early days had 2nd gens with a "pusher" pump on the frame rail supplementing the factory pump. It was powered with a relay using the factory pump wire to turn on the 2nd pump relay. It worked very well and the weak main lift pump would last a long time with pusher pump.
Larry

 

[JDoiron]

I now have a new Airtex E7151 on my 2002 Ram with a new VP-44. I have the Airtex mounted below the drivers door on the frame. I left the original carter lift pump in it's original location. The original lift pump is not powered but left plumbing in place for ease of installation. I only have 11lbs at idle and 4-7 while driving. Do I have a bad Airtex or is fuel passing thru old lift pump causing a problem? It seems to me that if the old lift pump is a restriction, the fuel pressure should go higher and not lower.

 

[NIsaacs]

It depends on where your fuel pressure sending unit is, if it is before the filter it would show high, if after it will show low if the oem pump is a restriction, and I think it is.

Nick

 

[JDoiron]

My gage is at the fitting going into the VP-44 so that would be after the stock filter. If stock pump is restricting the flow why should I not have higher gage pressure? All I know about flow and pressure is that a restriction would be harder to push thru fuel causing higher gage pressure. So confused.

 

[klcammie]

I run a pusher pump and when my lift pump went bad that is the numbers I had. After replacing the pump numbers were back up at 19 idle 17 cruise 7-8 WOT. If the oem lift pump is not running it will restrict the flow from the other pump. IMHO remove the oem or hook it back up.

 

[NIsaacs]

My gage is at the fitting going into the VP-44 so that would be after the stock filter. If stock pump is restricting the flow why should I not have higher gage pressure? All I know about flow and pressure is that a restriction would be harder to push thru fuel causing higher gage pressure. So confused.

The pressure is less because the oem pump is causing a restriction before the VP, where your gauge hooks up.

Nick

 

[JDoiron]

Thanks for all of the feedback. I will remove the old lift pump and see what difference it makes. I still have a hard time understanding why a restriction should not make gage pressure go higher and not lower. I'll give feedback when I remove stock lift pump. Anyone know of a transition piece available to put in the stock line in place of the old stock lift pump?

 

[NIsaacs]

I still have a hard time understanding why a restriction should not make gage pressure go higher and not lower.

I guess I am a poor teacher, lol

The restriction is before the gauge, so before the gauge reads the pressure there is a restriction (old pump) here the gauge would read higher. After the restriction, the VP bleeds off excess fuel via the relief valve, so now with less fuel flow (the pump restriction) the pressure is less because the pressure/volume is now less because it's partially stopped, again at the old pump.

Nick

 

[JDoiron]

Sounds like a plan, thanks

 

[JDoiron]

I removed the old lift pump and ran the stock fuel line directly to the stock fuel filter. When I cranked the truck the gage showed 16 lbs. That was way more than I saw pushing fuel thru the stock carter pump. I took the truck for a ride and it never showed lower than 14 lbs while driving. This morning I took the truck out and after several miles the gage went to zero. Then it came back to 15 then 10 then zero. While driving back home the gage pressure went from 16 to zero and all in between. It is like something is restricting fuel from the tank to the frame mounted lift pump. Is there anything in the tank that could be plugging the fuel inlet line? What is my next step since my fuel line is now ran properly.

 

[klcammie]

Yes there is a screen on the pick up tube, it could be dirty. To get to it you drop the tank or lift the bed. You could also change the return valve at the Vp They are no bad price wise. and a whole lot easier then the other. Genosgarage.com has them for 34.95.

 

[JDoiron]

I'm sorry but what return valve at the VP and where is that?

 

[NIsaacs]

It's the banjo bolt at the return line: http://www.genosgarage.com/product/valve-1467445003/276

Do you have a filter or screen on the inlet side of your lift pump? If not, the screen in the intake fitting of your lift pump might be plugged.

Nick

 

[JDoiron]

No screen from tank to frame mounted lift pump. I will be putting one on as soon as I find my problem. Where is this banjo bolt (return valve) located and what does this have with not being able to suck fuel from the tank? Sorry for all the stupid questions but I need my truck back on the road. Is it hard to drop the tank? It is full and that sux.

 

[NIsaacs]

Where is this banjo bolt (return valve) located and what does this have with not being able to suck fuel from the tank?

I didn't make the comment, just showing you where to get one if you need it. It is on the return line at the vp.

The tank is not bad to drop, but you will need to get some fuel out of it. I use a floor jack with someone to help balance it.

No question is stupid unless you don't ask.

Nick

 

[JDoiron]

I disconnected the fuel line to the frame mounted lift pump. I made a fitting to attach a blow line to the fuel tank. I blew on it by mouth and could hardly blow thru it so I put my air compressor on the line and blew gently. After that, I could blow by mouth but not too easy. I syphoned the tank and set up my floor jack for tomorrow. There were lots of small black particles in the diesel so I strained all the fuel before putting it in cans. While I was under the truck, I ran a line from the lift pump to a jug of diesel. I cranked the truck and it ran great. It had 15-16 lbs at idle and revving it up it only dropped to 13-14. I think my problem is the strainer in the tank. I will find out early tomorrow if we don't float away with all the rain in Louisiana. Can anyone let me know if there is a video or something to remove those fittings on top of the tank. Thanks to all.

 

[klcammie]

I'm sorry but what return valve at the VP and where is that?

Here is a pix. It is the banjo to the left.

. The one with the hose is the supply, the hose is going to the fuel pressure sender.