So this is the second time I have posted on this topic. I have run through all the previously suggested tests and I'm still having the same problem. I have replaced the fuel pump, only to find that I wasted $75.00. I did come acrossed an issue that I could see would cause a fuel pressure issue. The hose that connects the pump to the sending unit was split down the side and basically shooting gasoline back down into the tank. Attached is a pic of what I removed and replaced. I'm pretty sure the pump is still good but I replaced it anyways because with the hose like that I simply dont know how long that pump has been over working itself. With the new fuel pump, I still only get 26psi running pressure, but the static pressure is holding at about 36 pis(key on engine off)
The diaphragm on the fuel pressure regulator seams to be holding a vacuum well, and isnt leaking any fuel. The injectors dont seam to be leaking off per the test I ran. I have a timing light that I'm going to hook up to it and replace the fuel filter again. Any other suggestions would be helpful.
Pinch off the return line to the tank at the pressure regulator and see what the pressure measures.
August, 26, 2012 AT 5:34 PM
Symptoms indicates the fuel pressure regulator is faulty.
August, 26, 2012 AT 5:38 PM
OK, the pressure went up to about 50psi. Does that explain it?
August, 26, 2012 AT 5:45 PM
Yup, that means a bad pressure regulator.
August, 26, 2012 AT 6:11 PM
Ok, I unhooked the vacuum line off the fpr and the pressure went up to normal operating pressure 35-36 psi
August, 26, 2012 AT 6:25 PM
35-36 psi is at lower edge of specs but vacuum line should be attached.
August, 26, 2012 AT 7:19 PM
That is normal. With no vacuum, the pressure should rise.
August, 26, 2012 AT 7:27 PM
Put a brand new regulator on it with no change in results it seams the regulator works properly without a vacuum line hooked to it?
August, 26, 2012 AT 7:33 PM
With vacuum, it will lower the pressure. Thats normal as I said before.
What kind of pump did you use?
August, 26, 2012 AT 7:51 PM
The name brand on the pump is airtek.
Now the truck is getting 26psi @ idle but if I give it a little more throttle, the pressure goes up to 36psi. Naturally a higher rpm is going to require more volume @the same pressure correct? So, does that mean the regulator is operating correctly? Maybe the old regulator was bad and I just need to take it for a spin and see what happens in stead of looking at the pressure gauge.