Testing fuel pressure part 2 (97 lesabre

[inafogg]

http://www.automotiveforums.com/vbul....php?t=1051068
OK GUYS,need some help if you read (part 1)fuel pump
lasted 2 days until long cranking time was back??
when i rechecked fuel pressure ZER0.hmmmm WHAT
happened.now you have to prime it 3 or 5 times or a shot
of ether to get it going.pressure only reads 20psi w/fpr vacuum
on or off & drops right off when engine is turned off.so i blocked off return line no difference key on 0, run 20, & wont hold pressure
when shut off.my question, is the FPR still in the loop when i
block return at fuel rail. i think it has to be because its before
the return line.if it is then i can see a bad regulator but if not
it puts me back to pump/lines to see what i did wrong
Thanks again mike

[maxwedge]

If you block the return line and the pressure stays up the rreg is bad, if it still drops you have a bad injector ( or 2?).

[inafogg]

i blocked return, pressure stays at 20 running of course .key on e/off zero psi
can i unplug injector harness to verify its a stuck injector??i still believe
if im not getting enough pressure to begin with it still could be pump/line
so if the pressure stays the same??

[inafogg]

ok i was able to hook the pressure gauge up right at the fuel filter
10 psi & bleeds to nothing 0 psi when pump shuts off after its 5 sec
prime.is their a check valve on pump or tank??i gotta lower tank & have a
look.

[old_master]

There is a check valve at the outlet of the fuel pump, (part of the pump). If you have battery voltage and a good ground at the fuel pump connector, the pump is junk. What brand fuel pump did you install?

[inafogg]

delco

[inafogg]

hey guys,i pulled the pump back out again.i found that the retainer(plastic locking)
was cracked & allowing the seal to parctially blow out on the connecting pipe.
i replaced the retainer pressures back & holding but at 44 50 with reg.unpluged
i'll keep an eye on it over the next weeks
THANKS AGAIN Mike

[old_master]

The 44psi to 50psi, is that with the engine running? Fuel pressure specs are with the ignition in the run position, the engine off, and the fuel pump running. It doesn't matter if the fuel pressure regulator vacuum line is connected or not, when the engine is off there is no vacuum there. When the engine is running, manifold vacuum should be present at the regulator. Vacuum applied to the regulator causes fuel pressure to drop.

[inafogg]

im sorry,i was just closing a thread i started.as far as f/pressures i understand
as far as your question.44 was at idle 50 was w/fpr vacuum disconected
and it held 44psi w/turned off but psi specs are 47-55 so i'll keep an i on it
thanks again

[mrd2001]

I love Old_Masters new siggie.