60-62 on,no less then 55 in 10 min

 

Dealership mechanic should know better Apparently he didn't read the GM shop manual. Don't ever kink the return line when the pump is running. If you do, the pump will destroy the diaphragm in the regulator. Max pump pressure on your 2000 is 73psi to 108psi, if the regulator is exposed to anything above ~75psi it will rupture the diaphragm in a heartbeat.

Key on, engine off, fuel pump running, pressure must be 60psi to 66psi, (this is your regulated fuel pressure). It must remain above 55psi for at least 10 minutes after the pump shuts off. GM does not publish any "engine running" fuel pressure specs for this engine, there are far too many variables involved.

 

Ok, so if his suggestion can cause more harm. Then what should I do instead? I wanna try and get this running in the next week or so.

Thanks for psi info

 

On your 2000, in the underhood fuse panel there is a vacant terminal. The circuit runs directly to the fuel pump, it's called "pump prime". It's used for activating the fuel pump to test fuel pressure and leakdown.



Connect a fuel pressure tester to the service port next to the distributor. Connect a jumper wire from battery positive to the pump prime terminal. When the fuel pressure stabilizes, make a note of it. Disconnect the jumper wire, wait 10 minutes and make a note of the fuel pressure. The first reading, (pump running) must be 60psi to 66psi. The second reading, (pump off) must be above 55psi. Post both readings.

The results will tell if the fuel delivery system is working properly. If either reading is out of spec, there's a problem, and more tests are necessary.