hey guys, thought my overflow valve was bad but i guess it must be the lift pump cuz i got a new of valve and the problem isnt fixed. so i was told i only need a fass 95. it seems like everyone runs the 150 though. whats the difference/benefit to the bigger one? and is airdog vs. fass personal preference ir is one better than the other? thanks guys-chuck

 

Who told you that you only need a FASS 95?? FYI, you will need a lift pump that will supply the following: 18-24 psi at idle, 28-36 at 2000 rpm with no load. I dont think a 95 gph pump is going to do it, especially with the performance mods you have.

Why dont you just replace the stock lift pump? Its a lot cheaper than a FASS or Airdog.

 

definately get a 150 they are like the same price so why go with a 95, and yeah on a 12v the stock one is fine unless you just want to upgrade. i would go with a the airdog because its adjustable or the new adjustable FASS one.

 

yer lift pump is driven off a cam lobe and the best there is...........................stay with the OEM pump fer yer truck


on my 01 I run the 95 gpm and it works very well

 

Have you cleaned your prefilter screen?

 

thanks for the lift pump info. yeah a guy on cumminsforum told me i need a 95. i guess ill stick with the stocker then.i havent checked my screen yet. im going to do that first thing in the morning. i go to night school at wyotech or id do it right now. i asked a light duty diesel instructor here and he was of no help. i was wondering if running ULSD killed my injection pump? i looked on alldata to try to figure this out but i already did everything it says to.

 

Hold on here...am I missing something?? You are asking about your lift pump and then talk about ULSD killing your injection pump.

Is it your lift pump thats dead or the injection pump?


BTW, the stock 12V lift pump is around $140

 

haha sorry, im getting my posts confused. i have no idea whats wrong with my truck. the overflow valve is brand new and when i pinch the return line the pressure spikes but im at 10psi at idle. i am trying to figure out what exactly the problem is. obviously i have a restriction somewhere or a bad lift or injection pump.

 

What happens if you pinch the return line? If the pressure doesnt increase, then its the lift pump.

You could also try this:

Pull your over flow valve off the engine, take it to a vise, and remove the small bolt on the top of it. There is shims, a spring and a ball inside. Careful not to lose the shims. Get a retractable click pen, and take the spring out of it. Cut the pen spring to the same length as the original spring inside the OFV. Reassemble with both springs and the shims, and reinstall on the pump. If you want more pressure than what you have now, you can stretch the springs a bit, or take the remainder of the pen spring, cut it a bit longer, and use it with the stock spring. This is from a buddy of mine - he said his fp went from 14 psi to 40 psi.

 

when i pinch the line pressure goes to 50-60psi. the overflow valve is literally brand new i just put it on thismorning in hopes that it would fix it.