I have a 1987 Mercury Grand Marquis Colony Park Wagon. It has the 5.0 EFI 302 v8.


I had a leakey fuel tank so i decided to replace it. the car started and ran perfectly fine before i did this. it took 4 months of the car sitting there for this to be accomplished. I remove the old tank and pulled out the fuel pressure regulator, fuel pump and the fuel pump sending unit. all then putinto the brand new tank i picked up for a hell of a deal. but now the car wont start. the fuel pump hums when turned to on but no gas comes out of the line that i took off the fuel filter to check. the tank has about 4 gallons of gas in it so i dont think its a problem there. the engine cranks and everythings fine from the front its just not getting any fuel because you cant smell it up front either. what could be the problem? i dont think it could be the fuel pump relay but i will replace next. let me know your thoughts.. could it be the pump i mean. it did work fine before and it hums now. would it still not work? i really dont want to have to drop that tank again lol





also... my gas gauge always reads beyond full once i turn the car to any on or acc position. is there a ground somewhere in the wire.. the sending unit seems fine.. a little while back the reading was just off a little like 3/4 when it was full.. so maybe the sending unit is bad.


i guess we sacrifice things when we have cars that are old enough to drink [img]smileys/smiley2.gif[/img]

 

Sounds like the fuel system is not getting primed. Did you install all the old parts in the new tank? Sending unit is failing, but hopefully just bad grounding. Let me know if you''ve had any progress. Fuel filter change? Lots of crap on the bottom of the old tank?

 

did you crack the fuel filter and see if you get fuel through it? you might not get fuel to the motor so you next check if the fuel is pumping up to the fuel filter under the car.


do this first and tell me if you are getting fuel there or not before doing anything else like taking apart and reprimming it. ????


I think this is an easy fix, check out the fuel filter flow first

 

well i replaced the fuel relay and the filter.. the old one wasn''t clogged. and i test if the pump is pumping by leaving the line off that goes to the filter and not a thing comes out.. the pump still hums and nothing happens i put 2 more gallons in it to be sure and still no luck... i guess im going to dropthe tank again. and see if the line is crimped before the filter because of all the moving in and out of the tanks... i should also test the voltage to thepump then i guess. it just seems weird that it sounds like it works and dont.. and it worked before too...

 

I think you have to drop the tank. something is wrong in the tank. was this a used performance part that you got a great deal on and dropped the new pump in, or was the pump already in it?


try to tap the pump with a hammer on the tank. usea brass hammer or pinso no sparks come out. I hammer will work,you really don''''t need to tap hard just be careful. have the pump rumming with the line to the fuel pump still open when you do this. tap it and see if some gas comes out. Sometimes these get stuck or something is stuck in it. a little tap can free these up becsuse they spin sp fast and they just need a little help and then they flow


A side note, at the race track we use to blow a small amount of air from the air compressor in the open line with the filter to unstick the fuel pumps. It worked about 25% of the time. I just thought I would through out a few tricks before you have to drop the whole tank again.


let me know how it worksEdited by: jason sereiko

 

I think you should do want J Sereiko said before dropping the tank. I had to drop my gas tank once on my 1989 Granmarquis and it is a plain in the butt. What i did is go to the junk yard and got a newer fuel pump, i thinkit was for1993mercury. I fit it in the tank and before i put the tank together back in place i made sure that the car started. I am only telling you this because if you decide to drop the tank make sure that all your connections are right and that you put that fuel pump in there right. Also, your fuel gauge might a wire in the tank that might be pitch in there.Reminderdon''t forget to start the car. Good luck and hope this works.[img]smileys/smiley4.gif[/img]

 

If you are going to drop the tank, then just get new stuff and be done with this nightmare.


If you are on a budget like all racers are, then try the tricks for the pump and if you don''t have cash, then go with a good used one. but if i had the money i would justget a new unit since you are saving a ton of money doing it yourself.


try the air in the fuel line. It works. try the brass hammer also, it works.