Fuel Mileage

[Tbars4]

...it will be the hand pump...

 

[nooberiffic]

Okay. Did not get to the vacuum test...

Fuel pressure test as follows

Fuel pressure with key on engine off is 15.75PSI
Fuel pressure with engine on is 33.5 PSI at idle. Does not fluctuate as RPM increases. When I turn the engine off the PSI jumps up to 38 and stays. I waited five minutes and it stayed at 38 till I hit the pressure release valve.

I tested it a second time to see what happened with the pressure if I cycled the fuel pump a couple times. The pressure rose to about 22 PSI (engine off).

 

[nooberiffic]

did the fuel pressure tests again with the same result (except it seemed to pressure up a little faster today with engine off)

hooked up the vacuum tester to the FPR, and pressurised. Dropped about 4 psi.

just out of curiosity I unhooked the FPR's vacuum line from the intake and the fuel pressure jumped to 39 (engine running)

I also tested vacuum through the same intake connected and hg was steady at 11. The manual (that came with the vacuum tester) says its supposed to be 16 @ idle. I tested for all the problems it listed but passed them all.

Did I miss anything in my vacuum test?

And leads from this? The FPR and pump seem to be working fine.

 

[nooberiffic]

?

 

[nooberiffic]

no-one?

 

[nooberiffic]

with the vacuum at 11, I took the truck into the shop to get it checked out. They say they didnt adjust the valves properly when I had them do it over a year ago (after 500 mile break in). Compression at each cylinder was just 100 They are fixing everything under warranty.