So I have noticed that my fuel pressure has been dropping lower than it used to even under light acceleration, sometimes down to about 3psi. I am not sure it is the lift pump, as it will sometimes pop back up to 10psi which is normal (8-10 at idle, 6-8 under accel). I saw this happen a while back and figured maybe a clogged fuel filter. I changed it and found it was not clogged nor was there any junk in the housing. It started acting up again on my recent trip to PA and NJ. I did a filter housing drain and what came out was pure clean no water diesel. I had time to think on the long drive back, and figure there are 3 possibilities for what's happening. 1) Pump is getting weak and ready to crap out (it has 168K miles on it). 2) Bad electronic sensor for fuel pressure gauge. 3) Crap blocking the screen at the pump intake. I am leaning towards number 3 as the most likely culprit, but to check that I'm gonna have to lift the bed or drop the tank.

My next train of thought is if I'm gonna have to go to all that trouble I may as well just install an Air Dog while I'm that far into it. Now if I do go that route I want to swim up stream as usual and retain my factory fuel filter in the loop, and use a modified fuel module instead of a draw straw set up.

After doing a little reading on the Air dog, it seems that I should probably go with the 150. The 100 would probably be more than enough, but my ultimate goal is somewhere around 600 - 650 hp and the 100 says it's only good up to 550......

Any input on all the above will be appreciated. I also am trying to think of a way to attach a temporary manual gauge and drive around some just to confirm my fuel pressure gauge is accurate. Input on that would be appreciated as well.

 

No opinions or experience on this subject?

 

Just my.02, but I believe you are on the right track with the gauge to confirm the problem.
Whatever you do GOOD luck in solving your dilema.
Be patient, there are a lot of knowlegable guys on here to help you.

 

Thanks sojoe.