1989Formula5.0

Hello everyone!

I am having a problem with my 1989 305 CID, 5.0 L, TPI, Auto-Trans Car where the check valve in the fuel tank will not hold pressure. I have performed the vacuum test and it does not hold 15 psi for 60 seconds as the manual indicates it should.

To clarify the part I am looking at, it is attached to the fuel sending unit, and it is the plastic piece (ball valve) on the underside of the assembly. The numbers 3675 are stamped on the bottom of the part.

Knowing that the part is bad, I diligently set about locating its replacement. No dice.

Does anyone know where I can find one or if anyone manufactures an aftermarket replacement?

Any help is greatly appreciated.

Thanks.

Tuned Performance

iTrader: (92)

there is no check valve in the tank. are you referring to the vent valve or fuel pump damper? sounds like you have a bad injector or fuel pressure regulator.

Tuned Performance

iTrader: (92)

this is just used to isolate the fuel pump so noise doesnt travel through the supply line.

1989Formula5.0

Thanks for the reply tunedperformanc,

I guess I am referring to the vent valve as my car doesn't have a fuel pump dampener.

Essentially, what my car is doing is not starting. I can get it to start with starter fluid and it will sit very happily in the driveway and purr like a kitten. That is until I try to get the lazy b***h to go anywhere. At that point it is a 50/50 shot as to whether it will stall when put in gear or run like crap and not exceed 2500 rpm's. I have heard some refer to this as limp mode. To add another weird wrinkle, the car runs when I take out the fuse for the fuel pump (under dash not relay). If you put it back in it kills the car. I know I have an intermitant fuel pressure problem I just don't know why.

In addition, I think the I have some mystery cooling problem. The thermostat does not open properly (thermostat and radiator have been replaced and the system has been bled). The driver's side fan comes on at strange intervals and I have never seen the passenger side fan come on.

Since I have gotten it I have replaced the following:
Battery
Plugs
Wires
Radiator
Thermostat
Ignition Control Module
Distributor Cap
Rotor Button
Coolant Temperature Sensor (Front of Engine Under Throttle Body)
Knock Sensor
Fuel Pump
Fuel Filter
Fuel Pump Relay
Intake and Manifold Gaskets
All Vacuum Lines and Hoses
Fuel Cap
Schrader Valve on the Fuel Rail
Belt
Timing Chain and Crank/Cam Gears

The only "Mod" made to the car is that the EGR stuff has been taken out and the heater core has been bypassed due to leakage.

The PCM checks out on all pins, the knock sensor shows variation when tapped, the car does not stall or stutter when the MAF or PCM are tapped.

As always, any input is appreciated.