2.5 Fuel Pressure ? something is not right here (Page 1/3) Lou6t4gto FEB 09, 04:35 PM 1985 2.5 / automatic. Put in a shrader valve, car will go to exactly 13 PSI "while It's RUNNING". as soon a,s (immediately) when the key is shut off, it goes to" 0"! not gradually, within a half second ! isn't it supposed to HOLD pressure for at least a couple of minutes ??? Thanks Lou6t4gto FEB 09, 05:48 PM pinched the inlet tube, then shut it down, No Difference. I installed a" used" Pressure regulator I have and it did not make any difference in the "DROP", BUT, the" Volume" of fuel from the cone sprayed from the injector got to be a "FINER Mist" ! took apart the old regulator, no rips, but had a very small chip of metal in it (Maybe blocking the valve )? But still, WHY the PRESSURE DROP so fast ? kzelisko FEB 11, 04:58 PM There is a check valve on the pressure side, I believe it's in the fuel pump, that should maintain fuel pressure after the pump shuts off. They are frequently bad on most older gm's. Lou6t4gto FEB 11, 06:45 PM thats why I pinched off the supply line then shut it off. I drops even with the supply shut off. Lou6t4gto JUL 20, 07:15 PM Was a Split rubber Line in the tank !.....New pump, new Lines, now holds Steady 10psi Patrick JUL 20, 09:36 PM quote Originally posted by Lou6t4gto: Was a Split rubber Line in the tank !.....New pump, new Lines, now holds Steady 10psi Your posts are difficult to follow. quote Originally posted by Lou6t4gto four days ago Here: was a SPLIT rubber line IN the tank, replaced the Pump And line. Car STILL STALLS ! Lou6t4gto JUL 20, 09:50 PM the car now has Literally EVERYTHING , every sensor, pump, ECM, icm, pickup coil, realays......NEW, yet it will still quit without warning. sometimes go 5 miles fine, another time won't move 50 feet without stalling 5 times! but always starts right back up. sometimes stalls again, sometimes another 5 miles. Lou6t4gto SEP 05, 06:26 PM well it does Hold fuel pressure for awhile (could be 1- 20 min) then it ll drop to zero. car stalls. turn the key on again, fuel pump pumps, and it will run and hold pressure again... untill it won't ! LOL is the computer the only thing responsible for keeping the fuel pump pumping to" MAINTAIN" fuel flow ??? seajai SEP 05, 07:30 PM Have you checked all the grounds? Especially the ones for the computer. You could have an intermittently open wire in a harness somewhere. Perform a wiggle test on all the wire looms. Start the engine and move the harnesses around, if there is a bad wire or bad connection somewhere this should show it. Wiggle the connectors on all the sensors, this will show if you have any pins that are opened up a little and losing contact intermittently. If any of these tests cause a stall, you've found your culprit. Replacing parts is only half the job, you still need to test the wiring and connectors that link them all together. fierofool SEP 05, 11:02 PM If it just shuts down and won't start until the ignition is turned off then back on again, check the ignition switch down on the steering column. Several of us have had that problem to include L4's, 2.8's and 3800SC's. Changing out the ECM, coils, ICM or other sensors didn't work. The ignition had to be turned off for it to restart.