My pump should be back from rebuild in a couple of weeks. I've got the parts ordered to install a fuel pressure gauge. A couple of questions though. Can someone tell me the flow rate for a factory lift pump? It looks pretty simple to measure, but anyone got a link to the procedure? Google turns up several but they are all 2nd and 3rd gen. Anyone have a link to a pod or underdash mount to install my1 and a 1/2 inch gauge. All I've found are for 2 inch gauges. Thanks for any info.

 

Just curious why you want to know your flow rate?

 

IIRC, fuel flow rate is very important for the CR motors but not so much for the mechanical (ve and p-pump style) Diaphragm style is 3 to around 7lbs typically and with a HVLP you should see no more than 15 or you will lose the front seal in the IP.The reason alot of people switch to the HVLP is they have no diaphragm to rupture that will fill your pan with fuel.

 

My psi usually runs between 7-10.

 

Just to satisfy curiosity. A low pressure at the filter banjo bolt would mean a low flow or no fuel flow. A good reading would probably indicate adequate flow, but since the VE pump depends on adequate flow to cool the pump, the sure way to know would be a flow rate test. I probably wont worry about it since even my manual doesn't give the flow rate. It probably isn't important since my VW Bug has the same VE pump and doesn't even have a lift pump.

 

newb here-

What is considered a low flow rate?

source

 

If you have your VE or P-Pump turned up to the max fuel and your truck stumbles when you're rolling coal then you need more lift pump flow. Seriously I don't know what the flow rate is for different inj pump settings and how heavy your foot is.

I use a piston pump from DieselTuff and it shows 13 psi at idle and hasn't ever stumbled even while pulling my RV. But my VE is set to factory settings AFAIK my injectors are stock too. I have no need for more power but if I ever do I'm certain the piston pump will be adequate.

You might venture over to DieselTuff and see what his piston pump is rated at.

Edwin

 

That was the purpose of my post. I think I saw somewhere that .8 ltrs in 30 sec. of cranking was right, but I am not sure. A pressure reading of 7 should indicate a good stock system with adequate flow. I would feel safer to be able to measure both pressure and flow since the VE pump is cooled by fuel flow. A sufficient flow to run the engine may not leave enough circulating to cool the pump.

 

I bet the size of the fuel lines really comes into play if you are looking at the GPH flow rates.

 

I think the lift pump just suffices to get fuel to the pump. The VE has it's own pump to move things from there on. I ran for a long time with a bad lift pump while the VE just sucked fuel right through it. I only had a problem when I parked on a hill and the tank was low.

Edwin

 

Dodge does say that the fuel flow excess cools the pump, but as I said earlier, the VE4 in my VW ALH doesn't have a lift pump and it runs fine for the last 200k miles. The tank is higher and closer though. I'm not sure how much more heat is generated by the VE6 in a Dodge vs the VE4 in the ALH. I'm guessing that I'll go with just checking pressure since Dodge saw fit to give procedures for fuel flow for the P pump but not the VE pump.

 

0 psi at WOT. This is why it's important to install a pressure gauge between the LP and the IP.

 

AFAIK the return flow from the VE goes through a pinhole in the banjo on the back of the pump and joins the return line of the injectors before going back to the tank. I don't think the flow is that much and serves to heat the tank in winter more than anything. That's why there is a big coil of tubing that the return flows through before exiting at the bottom of the pickup assy. The coil is a heat exchanger to keep the fuel from gelling. Also there is a fuel heater at the top of the filter assy. for the same purpose. Of course I could be wrong and frequently am.

Edwin