Hey guys and gals
I just had my VP44 replaced, I was lucky it was covered under warrenty. I had a Glacier lift pump system with 17lbs of preasure when it failed. The problem was I had 17lbs of preasure that was mostly air. The sending unit failed, and when the fuel level dropped below 1/2 tank the lift pump would suck air and fuel. This caused the VP44 to fail. The fuel preasure was steady at 17lbs the whole time.
Fuel preasure is better than nothing, but it is NOT gospel. The only true measure is fuel volume. The VP44 needs 1.03 liters of fuel in 25 seconds. The glacier pump delivers 1.5 liters of fuel in 25 seconds, but it will also pump air, and 17lbs of air will not keep the VP44 cool or run the truck.

 

This is where many have found faith and hope in FASS.. fuel-air seperator's.

 

Excellent point! I mentioned before that after I installed a clear inline fuel filter, I am seeing small bursts of air going through it occasionally. I don't know where it is coming from. All I know I don;t like it! That air ends up in the IP and can not be good for it.
If I had not had the transparent filter, I would have never known this. Maybe many trucks have this going on. If I locate the "sucky" spot I will post about it.
I am also wondering if sucking air is Walbro's privilege. It pumps way more than a stock LP, creates more suction and may suck air where a stocker would not.
-P

 

May I ask where does the air, should it get sucked in, go in a FASS? Isn't FASS a closed system?
-P

 

I lost a VP with only 40K and "perfect" fuel pressure the whole time.

FP isn't the life jacket we want to believe it is.

jmo

 

Same here. VP went at 53k and always had good fuel pressure.

 

Glad to know all this AFTER I got the walbro... Guess I need to get some clear fuel line and run a loop of it infront of my windsheild so I can let off when I start seeing air...

 

FASS has a return line from the pump to the filler neck....

 

Another reason to keep your fuel tank full. I have 210K miles on my original VP-44. I rarely let the tank get below 1/2 especially around town & stop & go traffic. Sloshing diesel fuel picks up air bubbles and holds them. The bubbles get picked up in the fuel system. The extra fuel also cools the VP. If you always run 1/4 tank or less that fuel heats up and can't cool, more fuel in the tank, more cooling.

VP-44's can fail for many reasons, if treated right (and with a little luck) they can last 300K miles, or more.

Keep your fuel tank full, it's a good habit to get into when you drive a diesel. Just use 1/2 as your empty mark, that's all.

 

I do not think that I would trust that. If your module in the tank fails like mine did I think your VP will also fail. So far the best idea I have heard was Pauldaisy's clear fuel filter, assuming we open the hood now and again and look for air. A full tank of fuel would also work, but it is not allways an option. Running across the country and never going below 1/2 a tank of fuel would suck.

 

Geico is correct...most people tend to think that air in the fuel isnt an issue. Air in the fuel causes cavitation which wears pumps. I usually keep my tank full too - in the winter, a full tank reduces condensation/corrosion and in the summer a full tank helps cool the fuel return supply which helps to cool the VP-44.

 

I agree it helps.... but to quote HOHN....it isn't a life jacket either!
He and I....and many others religiously filled at 1/2 tank....used diesel fuel treatments... monitor FP... separate entrained air, etc. and still lost VP-44's before 100,000 miles.

Geico 266 has the exception to the rule - a durable injector pump. One of the very few. I'm happy for him.
I'm just not convinced there is any preventative maintenance that is even 80% effective in extending VP-44 life.
JMO - RJ

 

I've seen the FASS display, with clear plastic fuel lines from the FASS to the injector pump...and from the FASS to the tank (return line).
It's quite impressive, IMO, to see all the air bubbles in the return line but none in the fuel line to the pump.
The air is separated at the twin filters and routed back to the tank.
Older FASS systems returned the fuel (and air) to the filler vent tube. Newer models have it plumbed into the tank return line ... allowing refills with the engine running.

RJ

 

true enough - point taken. With the VP-44 its almost a crap shoot...Ive got close to 80 k on my original pump and my fingers are firmly crossed now that I dont have any warranty left.

Yeah, the FASS display is pretty interesting.

 

How can one be sure they are getting a new system, as I have also heard that the brand new ones are also much quieter??