So a few weeks ago I went to change my fuel filter and to my luck broke 2 out of the three clips that connect the fuel lines to the filter, the two that go from tank to filter. I replaced the line with some dorman fuel line repair kits and now my truck is having problems starting because of the fuel pressure. I went and had it pressure checked and at the end of the fuel rail by the injectors there is 70 psi of pressure. My truck is only supposed to have 35-50 psi. Now the other problem is that there should remain a constant pressure after I turn the motor off and within 5 seconds of turning the engine off the fuel pressure is back at zero psi.

What is going on and what do I need to do to fix this problem. I want to solve it before I have a lot more issues.

Thanks all

(2002 Ranger 4.0)

 

Anybody have any ideas at all?

 

what did the fuel-line repair kit consist of?

the loss of pressure after you key off sounds like a check-valve issue, but the check valve is located in the fuel pump assembly, so damage done to the fuel filter and surrounding area shouldnt have affected the check valve.

when you checked the pressure at the fuel rail, was it with the engine running?

 

The correct fuel pressure for a 2002 4.0L is 64psi +/- 8psi. This needs no repair.


These are some possible causes for the rapid pressure drop when the key is turned off. The pressure drop may or may not be the main cause of the hard starting condition though.

• external fuel leak
• leaking pulse damper (on the fuel rail)
• bad check valve in the tank pump assembly

 

How would I go about checking to see if the check valve assembly is in fact bad inside the pump.

Also the fuel line repair kit consisted of new hose, a new clip to attach to the fuel filter and a sleeve to attach the old and new hoses together. I dont know if this could be where I am losing pressure or not though.