I just got the truck 1000 miles ago, it's a 1994 2WD manual with 151K. The truck drives fine under normal low RPM fuel saving type conditions but it seems to die off or "lose power" at around 2000 rpm. I installed gauges and the fuel pressure is only at 10PSI at an idle and does not get any higher at all but it does drop! I got the screen kit and a fuel filter that I am going to do today but I was curious of what else to look at if it persists or if I throw a lift pump at it.

 

you need a lift pump to low of pressure it should have 25 at idle

 

I am aware that it should have 18psi minimum at idle, maybe I was a bit unclear. I would prefer some advice on other areas to look at to be sure it's the pump, although I doubt it's not the pump I want to make sure everything is rite prior to installing a new one to make sure it is the pump and to insure the new pump is working correctly. I have not ever dealt with one of these pumps, well the entire 12v setup is new to me so I would like to learn.
I plan on getting the system up to par and then adding a better filter system to it.

 

well u can start with a pinch test u can pinch the return line and see if the pressure goes up and run better

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go with an air dog 150 they are 499.00 and u get the 2micron and 10 micron filters as well as a great pump with a lifetime warrenty

 

I don't think I need the $500 setup, I will get the system working as it should and throw in another filter. IMO putting in an electric pump would only complicate the simple mechanical system I have now. Don't get me wrong I did a quick search for the air dog 150 and it's a nice looking, compact setup, I just think it's a bit more than I am looking for.

 

check for leaks in the feed line from the tank to the back of the engine, i used and electric air matress pump with a towel around the nozzel to fit in the filler neck (an idea I borrowed from someone here) or just replace with diesel rated rubber from the tank to the back of the engine. check the 1/2" rubber hose between the prefilter and lift pump, mine was cracked where it couldnt be seen. check the metal lines coming off the tank fuel sending unit.

 

You put some pressure to the system and found the leaks, sounds like a good idea. I may just figure out how much hose and do all the rubber lines anyway, the truck is almost 16 years old and it's rubber lines do have a life span. The truck was out of fuel when I bought it and took around 4 hours to get it to start, I want to do as much as possible at the same time so I only have to prime the system once.
I think I have a few ideas of what to do, now I just need to convince my wife that watching the gauge for me while I pinch the return line is something she wants to do, and that me doing some work on Thanksgiving is ok or at least better than football.

 

just tell her that watching the gauge could save u money and time by eliminating the overflow valve as a suspect. I just finished putting a draw straw in today..unfortunately they sent it with the wrong size fitting so i have to wait a few days before i put the tank back on. if the metal lines on top the sending unit leak u have 3 options..1. draw straw $50 (some small modifications to the sending unit and cutting the tube on the draw straw required)..2.there is a company that makes just the replacement line assemble that looks like the original $160 or 3.replace the whole sending unit...$300

 

put a new check valve in my truck fuel presure went from 10 psi to 21psi just a thought.

 

sounds like a weak overflow valve spring to me