Hi, ive seen a lot of issues with 1989 CORVETTE starting hard/long crank time, , mine is doing the same, ive replace 3 fuel pumps , 2 regulaters , when i put a fuel pressure test gauge on it pressure is good at 40 psi my problem is as soon as the fuel pump stops or key is turn off the pressure drops fast only 2 or 3 sec. and its at 0. what im i missing?

 

Welcome to the forums, Sounds like a bad regulator, but 2 replacements makes me think that's not it. A stuck open injector would leak pressure off, maybe. It would run rich with a bad injector, with a dark spark plug or a miss. Or a bad check valve in the fuel line between the fuel pump and the fuel rail. I'm not positive about where it's located, though it was on the fuel pump pressure side near or in the pump, Or you could install a check valve in the fuel line from the pump if that's the case.

 

The system is not designed to hold pressure with the key off.
You may need to look into the ignition system and make sure the injectors are getting the proper signal while cranking.

 

Hmmmm.... the way ive read some off the post they say how to check the fuel pump to hold pressure and FSM does the same thing, I sure hope what you say is true because ive also tried 3 different fuel pressure testers and get the same readings.
The car runs great after starting it , no missing or hesitation .
Even tho its a 1989 corvette its has 31k on it and looks great , so im sure hoping you are correct and get on with my life LOL
Thanks so much for the quick reply

 

Check the fuel line pressure when cranking the engine over, there should be 40 psi or something close for it to start. I believe your line pressure drops off when cranking making a no start situation. In start mode the fuel pump is not in running mode. Good chance the check valve is not working from the fuel pump to hold enough pressure to start. You can place a jumper wire in the fuse box to override the pump off in start mode to see if that makes a difference in starting, then remove the jumper after starting. I would check your old fuel pumps for a check valves.

 

welcome Tom