out of things to replace
#13
Back to post #8.... What is the pressure with the ignition ON, engine OFF, and fuel pump running? Then, what is the pressure 10 minutes after the pump shuts off? GM does not publish any "engine running" specs, all fuel pressure readings are taken with the engine off.
#16
Now we're gettin' somewhere! Pressure is acceptable but leakdown is excessive. Next step is figure out what's leaking. Provided there are no external leaks, the leakdown problem could be in the tank, or in the plenum. To determine which one requires modification of the fuel pressure tester so it will connect directly to the outlet of the fuel filter. This will require some "creative plumbing" on your part. If you're not comfortable with this, take it to a shop that has the equipment and a competent technician.
#20
Should be 73psi to 108psi. Was the tester connected to the filter so all fuel pressure and flow ended at the tester? If not, it's indicating an inconsistency in leakdown from your other test, which is neither here nor there at this point.
EDIT: Bottom line what we're doing is isolating the pump from the plenum and checking maximum pump output pressure and leakdown in the tank.
EDIT: Bottom line what we're doing is isolating the pump from the plenum and checking maximum pump output pressure and leakdown in the tank.
Last edited by Captain Hook; 03-17-2013 at 07:17 PM.