Hi guys
My 89 Grand Marquis 5.0L engine cranks but will not start until I spray gas in to the air intake .with fuel pump pressure 38 psi.
the following items been replaced as follow.
1- fuel pump
2-fuel pressure regulator
3- EEC or ECU
4- spark plugs , cables , rotors
Note:- the fuel pressure drops from 38 psi to zero within 02:30 hrs
I know that I have 2 issues.
1- fuel leak back to the tank or from the spray nozzles that can be fixed.
2- why do I have to spry gas to the air intake to start the engine.
can you help please.

 

I have a buddy who's '89 GM (Grand Marquis) has the same issues. I'm not sure that I can directly answer your questions, as I haven't really dived into my buddy's Merc. We have the exact same ailments though. However, there's a youtube channel called bah53, who has an '88 Crown Vic these same problems, and shows how to fix them. His videos are concise, and 100% worth watching. If you're still having pressure issues, I'd make sure all the lines are good, could be a sneaky hole somewhere, or even on the new pump. Have you replaced the fuel filter? Who knows if that'd fix anything, but you never know... then it could also be electrical, but then you did alot of that ignition work... really tough to say. My buddy's car is in a shop with a mechanic, so once he gets back to us with some answers I can update here.

Anyway, best of luck, hope that helps!
Cheers!