I have a 2000 Taurus, 104K miles, 3.0 DOHC engine, auto trans.
This situation has happened to me 4 times within the past 7 weeks, and seems to occur at random.
The problem (so far) typically occurs after a short drive (approx 5 miles), and after the car has sat for at least a few hours (as when driving home from work or shopping). I'll stop to pick up my mail at the apartment complex, shutting off the car for about 1-2 minutes. Then as I'm driving away, the engine dies and will crank but not start as if out of fuel. After letting the car sit for about 30 minutes or more, it will start and run normally. I have determined that after the engine dies, the fuel pump is not running, as I cannot hear it run-up when the ignition is turned on. When I do hear the fuel pump run-up, the engine starts fine. I have subsequently replaced the fuel filter and fuel pump relay (in fuse box under hood) and it would seem the only thing left is the fuel pump itself. I took it to a dealer and they were no help, since their diagnostic machine didn't see a fault code. I am hesitant to replace the fuel pump ($600 job!) Unless I know for sure that this is the culprit and will solve the problem. Also, this does NOT happen only on very hot days, and the car has always had at least 1/2 tank of fuel when it occurred (these always seem to be suggested causes).
Is there anything else that could cause an intermittent fuel pump failure? It seems to me that if the fuel pump were bad, it would be more obvious and just stop running for good.
This is not the problem as it does NOT occur only on hot days (see original post). When the problem occurs, the fuel pump is definitely NOT running, so it is something causing interruption of the fuel pump power, or maybe the fuel pump is wearing out, but my intuition is that the fuel pump would not just occassionaly decide to shut off if it were bad. Seems to me that a bad fuel pump would stop running altogether, not once every few weeks.
October, 20, 2007 AT 6:37 PM
If you are handy at tracing wires, you can look were the wires run behind the left inner fender, My 99 fuel pump wire chaffed all the way thru at that spot. Might be grounding there intermittently.
Sorry about this miss! I read a boatload of posts and sometimes I try to get more than my share!
October, 20, 2007 AT 9:32 PM
I had same problem. 2000 Taurus w/101,000 miles.
Check the EMERGENCY FUEL SHUT OFF SWITCH located in trunk, right side, under felt (under decal).
Jumpered out switch & fuel pump started (so did car).
October, 21, 2007 AT 6:15 AM
Inertia switch tripped would be a constant, not intermittent problem!
October, 27, 2007 AT 11:14 PM
Switch is not " tripped", it's defective. After it cools off, circuit is closed, fuel pump runs, and car starts.
December, 1, 2007 AT 2:19 PM
Update. Looks like it was the fuel pump after all. Had it replaced several weeks ago and haven't had a problem yet. I don't mind spending the money for a fuel pump, but just wanted to be sure it was the right solution. After determining that there was power going to the fuel pump even when the problem existed, I was pretty sure it must be the pump. My guess is that there's a pressure sensor in the pump that cycles on/off the motor that must have been going bad. Does this sound right to any knowledegable Ford mechanics out there?
So. I'm good to go, and I hope this will help someone else down the road.
Thanks for everyone's input.
December, 1, 2007 AT 2:28 PM
Pressure regulator is on the fuel rail, it returns unused fuel to the tank, pump will run all the time when car is running.
December, 3, 2007 AT 11:05 PM
That would be logical, but why does the pump shut off when the ignition is turned on and the engine not yet cranked over (with good pump) if there's no pressure shutoff to the pump motor? What then might cause the pump to shut off and not restart after first starting the engine, then run again after sitting for a few minutes (when it had the problem), but not stop running at any other time while driving normally?
Even though it's fixed, I'd like to understand what could've caused the problem, and why a new fuel pump cured it. It couldn't be the pump motor getting hot, because the problem would occur even if the engine was stone cold, and it only happened within 30 seconds after starting the engine.
December, 4, 2007 AT 2:08 PM
You have a relay thats powered for 2-3 secs, enough to pressurize the fuel system until it's started.