91 Lx 5.0 five speed hatch. He just put it together as he bought it as a roller. Car runs fine down the road. Come to a stop for over 2 minutes and it dies. Starts right back up. So I get it back to the shop and throw on a fuel pressure tester. 75 pounds of pressure. I know it should be 40. When it starts to die the fuel presuure drops to zero.So I change the fuel pump and filter. Same thing. Change the fuel pressure regulator same thing. Figure maybe I just had bad luck bought a new pump. Same thing. To date I have changed the ecm. map sensor fuel pump relay. I even tried unpluging the 02 sensors to put it into closed loop. Same thing

 

Try replacing the regulator again.

Definitely isn't right, and getting expensive to track down it seems. Good luck.

 

the regulator is new billit

 

Have you tried the same regulator on another car? Sometimes brand new parts are bad... I'm sure you've had a couple, you do a lot of work.

 

Whats the possibilities of maybe a restricted return line somewhere. Might be overdriving pump and causing it to shut down?

 

Could this also make the fuel pressure be at 75 pounds? Curious to know what the cause is.

 

Something in the power circuit?

 

I'd put my money on the restricted return line. Most fuel pumps can create 90psi or more and an FMU on a blown car uses this very scenario to increase fuel pressure. At a minimum it would explain the high pressure. Not sure about the total loss of pressure. FWIW .02

 

Yes guys I thought of that but I can drive it from here to Ruskin down the interstate. I got off and drove down to 41 and as long as I did not sit for over two minutes at a light it was fine.

 

you double checked the fuel pressure gauge?