My 2000 ram 2500 has always taken a bit too long to start due to fuel pressure taking too long to build up. I normally prime it 3x by putting the key in and putting to ignition first. I hooked up pressure guage on the fuel rail, and heres what i got. So If i put the key in and turn to ignition to hear the fuel pump turn on , the gauge needle jumps to 25psi. I then turn the key back off, and then back on to ignition only again, where this time it jumps from 25 to about 40ish psi. If i do it a 3rd time, it remains around that area like it should. Keeping the key to the ignition location i am able to watch the gauge needle drop in real time..kinda fast (which makes sense why it takes long to start each time). When truck engine is on however, there isnt a problem (shifts and accelerates just fine with or without a load in bed). I was going to replace the pump, but is there something else i can check for a leak first? The fuel pump sounds healthy, but obviously there is a leak somewhere either injector or inside the fuel pump?

 

You should be seeing closer to 49PSI after the third key on. You have a failing pump.

 

i think it was 45 but i'll double check tomorrow (i was just rounding off)

 

You should get to the 4# psi(should read 49 psi) on the first key on. Replace the pump and see if you still have the dropping pressure.

 

Well sure i could do that, but it could be something before that where the leak is. Dont wanna drop the tank and replace the pump until i have to. Was looking for suggestions for other possibilities

 

If you aren't seeing gas on the ground, then any leak/problem you have is going to be with the fuel pump module itself. It is replaced as a single unit, so, changing out the pump, will solve your issue. Delphi or Denso pump only please. Unless you like changing them....

 

Sounds good. Also i checked it again and the first key turn was 20psi. 2nd key turn built up to 45psi but almost instantly drops. Truck engine actually running stays at 45psi

 

So the pump is just getting weak, and the check valve has failed. (not unusual.....)

 

How long should it hold pressure? Mine only holds for about 10 min. It backs down to about 10 psi and hold it there for a long time. But no problem starting

 

Pretty sure there is a spec for it in the service manual, but, so far as I am concerned, so long as it doesn't immediately drop like a stone when the pump stops, and it actually gets above 40PSI at the initial key turn, its all good.