What is the normal pressure output of the fuel pump? '89 car.

[bryant.cw]

I put a meter on it and it read 62 psi cranking the motor, slowly dropping and holding at 55 psi after a few minutes with the key out of the ignition.

Does this sound in the right range? I'm trying to diagnose a slow to start issue.

It always starts, but seems to take too long, and it just seems like it should have more power. I changed the FPR and it drove -awesome- with more power, but after the ecu 'learned' the new parameters, it went back to normal.:letitout::letitout::letitout:

[jlevie]

I suspect that you measured the output pressure of the pump rather than the rail pressure. Only the pressure in the rail matters, meaning that you tee in the gage into the line that feeds the rail. Normal rail pressure when cranking the engine should be 3.0bar.

[erik325i]

As Jlevie said, it's supposed to be 3 bar (43.5psi) in an e30.

Erik

[bryant.cw]

yes, but how to I run a tee in between the FPR and the rail? It is not connected with a hose and clamp as I'm sure you know. I already returned the tester to autozone. I measure the supply to the FPR from the pump, I just wanted to see what the pump itself was putting out. I replaced the FPR and it runs better, but still takes too long to start. Oh wells.

60 ish sounds right if it is going to bump it down to regulate it at 3 bar and send some fuel back in the return line.

Bentley said to check the rail pressure at the cold start valve supply, but my 89 is not configured like that.