turbo79

I just bought a 1992 SHO I'm going to refurbish. Here's my first issue: When the key is turned on, the fuel pump continues to run regardless (I'm going by the sound).

Of course, I've seen to it that it has gas in the tank; the engines starts and runs, idles just fine, and there is no gas leaking anywhere. I know the fuel could be just returning to the tank via the bypass, so what sensor or device tells the pump to stop when the fuel pressure is adequate, or is the pump maybe being fooled into thinking the pressure is down?

jwko

sounds like a pressure regulator problem.

tbird100636

Uh...no. He said the pump is running continuosly. There more than likely is an issue with the Constant Controly Relay Module (CCRM, contains the fuel pump, PCM/EEC-IV, and radiator fan relays. Formerly know as the Intergrated Relay Control Module, or ICRM.) There is no pressure sensor on this generation of cars. The relay turns on for three seconds then turns off. Make sure the connector terminals are clean and free of corrosion. It is under the warning label shroud, next to the crash sensor. It is a wide connector.

__________________
Master ASE Certified L1 Chrysler Technician- still a Ford fan at heart.
1964 Thunderbird Hardtop- Chantily Beige- 390 FE 4V V8-Uncle's Car
1966 Thunderbird Convertible- Red- 390 FE 4V V8- Uncle's other car- waiting for paint and body work!!!
1967 Mustang Convertible- Blue- 289 V8- helping a friend re-assemble this classic

SHOZ123

Need to see what the FP is when at idle and why it isn't normal, or if it is why would it be if the pressure is normal.

A common failure in the SHO is a check valve on the return side. This is located in the FP module in the tank.

tbird100636

I'm not trying to be a d---, but you obviously did not read the whole thread. (Or your just half asleep)
His fuel pump runs continuosly when he turns the key on. He was wondering if there was some sort of sensor that would be fooling the PCM into running the pump continuosly. There is none on this vehicle. The CCRM is the most likely cause. He never said the fuel pressure was out of whack or he had any drivability concerns.

__________________
Master ASE Certified L1 Chrysler Technician- still a Ford fan at heart.
1964 Thunderbird Hardtop- Chantily Beige- 390 FE 4V V8-Uncle's Car
1966 Thunderbird Convertible- Red- 390 FE 4V V8- Uncle's other car- waiting for paint and body work!!!
1967 Mustang Convertible- Blue- 289 V8- helping a friend re-assemble this classic

turbo79

Hello.

I did clean the contacts between the CCRM and the wiring connector, but that didn't stop the problem. Will a computer read out on trouble codes identify problems with the CCRM? (No "Check Engine" light, and that light does self-test when I turn the ignition on.) Is the CCRM repairable? I imagine that this part is spendy, and electronics are generally not returnable, so I don't want to get one on speculation.

Another hint: the previous owner has bypassed the CCRM and hooked up a direct switch to the radiator fan, so maybe you are on to something.

I didn't mention driveability, because I wasn't sure if that would help to focus on the problem. The car does have low speed/light throttle issues, as if it is terribly lean, or running out of gas, but at more open or full throttle it runs OK (pretty fast too - this is a Taurus?) .