TPilaske

Great thread! Thanks for taking the time to tear into those LP's Gary! ;D<br><br><br>Alpine --- Looks mighty cold out there to be tearing apart a lift pump! Or changing one for that matter! <br><br><br>Tony

AlpineRAM

Tony: Well yes it was a little refreshing.. -15C (dunno in F) but if you have to drive.... I didn't have a spare LP, but I managed to fix mine with a bolt holding the checkball in. <br><br>Gary: I don't know what sensor you use, but soem of them have a dampener either in the sender or in the gauge to make for a steady readout. This is good for readability but bad to see fluctuations. I tapped into the banjo of the VP44 and found that I do have some pulsations there. (I had the LP running solo against a closed end and almost no fluctuations, running against the VP44 without the engine running even a little less pulsations- I was slightly above blowoff pressure for the valve in the VP44, and last measurement with the engine running)<br>Hence I do assume that the pulsations don't come from the LP. Maybe you get some if you have a sticking vane in the LP...<br><br>AlpineRAM<br><br>

TPilaske

[quote author=AlpineRAM link=board=4;threadid=16913;start=45#161955 date=1058689341]
Tony: Well yes it was a little refreshing.. -15C (dunno in F) but if you have to drive.... I didn't have a spare LP, but I managed to fix mine with a bolt holding the checkball in.
[/quote]

I'm thinking that's roughly 6° F.....

engcogod

I'm pretty sure I was reading somewhere about somone who relocated the lift pump right next to the fuel tank so it wouldn't be such a long pull for the fuel. And he said that the lift pump is made to suppy fuel not suck it for long distances. He said he had good luck with it. I read it on here or somewhere on turbo diesel register.....I'll try to find the link......

engcogod

Heres the link its from TDR: http://www.turbodieselregister.com/f...threadid=77891

StakeMan

Is it the distance from the tank or the distance above the fuel line that causes a problem.<br><br>When I unhooked the rubber fuel line that connects to the steel line from the tank I got a diesel shower. I think you have to think about the siphon effect from the tank.

engcogod

From what I was reading its the distance the lift pump has to suck the fuel from the tank that puts all the strain on that pump. The lift pumps are made to pump, not suck long distances.....

StakeMan

When I installed the Wildcat Diesel fuel line upgrade (upcoming article on the install) I was surprised at how fast the fuel can drain from the tank. <br><br>After looking at the stock fuel lines I now believe that one of the main causes of lift pump death is actually the restriction between the lift pump and the VP44. I saw an increase of 6 psi at the track. Don't ask how low it was before the line change.

Geico266

This is an oldie thread, but tons of great info. I thought I would post a reply to get it in the loop again for 2nd gen guys.

Great info!

george7941

Thanks, Geico. The original analysis by Guest was very impressive and Alpine Ram did bring up a very valid point about differential pressure. I found this thread most interesting and I had not read it before.