mustang565

Well the originall issue I had was the car would drive perfectly fine then randomly wouldnt start. I could drive it for two hours and it would run flalessly then I would turn the car off and it would turn on and run for about 3 seconds then turn off. It would do this for about an hour then turn on and start running normall again. Over the next week the problem would happen more and more often. Every time the car would crank for about 4 seconds then start. I put a fuel pressure gauge on the motor when it was having this problem and you could clearly see it start up and go to about 30 pounds then you could watch it drop to about 15 while the motor was running then shut off all in about four seconds . So I know it was a fuel issue. I haver checked the inertia switch in the trunk and it was fine so I switched the in tank fuel pump and fuel filter. And it worked, The motor would start up first crank and it ran great. It ran great unfortunatly for about a week. I drove the car a good amount to, but a few days ago I went out to start it and I am having the same problem. I havent been able to check the fuel pressure but Its doing the exact same thing. and the inertia switch is not flipped. What am I missing here any ideas or thoughts on what my next step should be? I was kind of leaning twords CCRM? At first I had the idea that the new fuel pump i had just put in went bad. but the next day it started right up and ran great, then today its wont start, it will run for about 4 seconds then shut off. Im stumped here so again any advice would be greatly apreciated.

DR.DIESEL

YOU NEED TO HAVE A SCANNER HOOKED UP WHEN THIS IS HAPPENING TO SEE IF THE COMPUTER IS COMMANDING THE FUEL PUMP ON.ALSO SUBSTITUE A KNOWN GOOD RELAY IN THE FUEL PUMP POSITION.YOU COULD ALSO TEST TO SEE IF YOU HAVE 12 VOLTS ON THE POWER SUPPLY PIN ON THE RELAY CONNECTOR IN 2 SPOTS,A GROUND PATH IN THE OTHER AND THE LAST SPOT IS THE FEED TO THE FUEL PUMP.

mustang51js

isnt there 2 fuel pumps on these cars one in the tank and one closer to the motor?

0949er

no there is only one fuel pump (that is above the fuel tank)

mustang51js

oh i was thinking fuel filters but i could be wrong on that to,and my fuel pump is in the tank

5.0 85 GT

i think there is a fuse under the hood ont he driver side for the pump relay or some jazz, try replacing that...your pump could have gone bad tho, i put one in my 88 cougar, it ran great for 1 day, then it died, put a new one in the next day and boom she runs perfect...knock on wood

mustang565

Well I replaced the CCRM and the problem is still occuring. Unfortunatly I do not have a scanner so i cant determine the problem that way

Maybe Im not understanding correctly, I thought the relays are located inside the CCRM? Is there another relay that I could just swap without replacing the whole CCRM? The one thing I havent done is check the power supply going to to the fuel pump, which in order to do so I need to drop the tank and test it right at the fuel pump, incase there is some obstruction in the wire. And yes I'v checked the fuse under the hood.What else could possibly be causing this to happen?? I mean theres the fuel pump, fuel filter, fuse and relay?? what else could casue this problem??