fuel pressure regulator...

[stonyman70]

What would be some symptoms that my fpr is going bad....I have a 93 xplorer.. Truck not wanting to idle until it gets warmer up.. Bout fifteen minutes... And if I drive it for bout thirty minutes and shut it off for twenty minutes... It wont start at all until the engine cools down... Bout n hour... Then it fires right up... Also wants to die when I make a left turn...(go figure)... I've changed fuel pump, pump relay, ecc relay, plugs, wires, and coil packs.. Only thing left is fpr..... Any ideas?????.... Thanks...

Stonyman..

 

[arco777]

Welcome to the forum.

If the FPR's reference (vacuum) line has fuel in it, that is a good sign of a leaking diaphragm. You can also test it with a fuel pressure gauge hooked up to the test port on the rail. Test by priming the pump (turn key to ON, let pump run and stop) and you should see the pressure jump up to 35-40psi. The pressure should last for at LEAST 10 minutes. If it leaks down, you have either a leaking injector or leaking FPR. The FPR should be regulating your running fuel pressure to the same - leave the pressure gauge on while running the engine. There can be fluctuations but the pressure shouldn't drop real low.

 

[Peder_y2k]

Did you replace the fuel filter with new? A partially blocked filter can creste the issues you described.

 

[vq5speed]

Could be lots of things a combination of things. But if I was to pick one thing to begin process of elimination I would replace the Coolant Temp Sensor. But also make sure you don't have any vacuum leaks. Test every connection make sure there tight.

 

[malohnes]

I think Arco is correct and that ought to be your first test.
But the coolant temp sensor could cause this symptom too, so can a faulty O2 sensor as well. These are easy to to test and replace.