Hello everyone,
I have owned a 2000 ford taurus for about 5-6 years now with about 130,000 miles with the standard 3.0L v6 and love the car but this problem is really starting to get to me. It seems to be happening again and this would be the 4th time replacing the fuel pump in this vehicle.
It seems like it happens around once every year to year and a half that the fuel pump will fail. Starting first only certain conditions where the car has been driven for a while and when you get on the gas over 4000 RPM under load the car will stuter, but only after it is driven for 20 mins or more first. When cold will operate just fine. And will progress to the point that even if the car has been running for 5 mins any load will stall the car if it gets any load but weird thing is that it will idle just fine. Put in gear and tap the gas will stall out. Currently this one has not yet got that bad. With previous tests before monitoring the voltage to the pump I can see that is pegged at 12v and that fuel pressure will be almost at nill when this happend. Let the car cool for a while and will seem to operate again for a little while.
The last time this happened in the summer of 07 I replaced the pump and also the fuel pump voltage regulater that is in the trunk and was working a little longer got passed the one year mark, but is happening again. I have also (multiple times) replaced the fuel filter and blew air thru the line to see if it was clogged and seems to be flowing just fine. When I have the gas tank down the last time there was only one very tiny spot of a little corrosion and no rust. I take notice that the filters on the pump are dirty brown and have checked around with a mirror and don’t see any rust and there is no visible seddiment in the tank. I have no idea what else might be causing it. And am now starting to be at my wits end and have really no other ideas. Since it first happened I have almost always kept atleast half a tank of gas and never less then 1/4 tank, I don’t hammer the vehicle at all, most of the time unless getting on the highway I never have it above 2500 RPM at all. Every other aspect of driveabilty also seems to still work flawlessly.
I really have no idea why Ford did this, on every other car you have the fuel pressure regulator that depending on the pressure will just open up and let escess gas flow thru a return line back to the tank. On this car it is a completly different design which I beleive is the root cause of all of this. On this car the fuel pressure regulator is just a electric switch which feed to the PCM and a fuel pump voltage regulator which will turn up or lower the voltage going to the fuel pump to control the pressure that way. And it seems to me that something is just not working right and burning out the fuel pump way to quick for some reason.
The fuel pressure regulater voltages seems to be working in spec with what my haynes manual states. The only other things that I think might be causing it is the fuel pressure regulator over driving the pump, something with the fuel injectors staying open intermitantly (but tests fine with voltage you will hear open and close), or possibly something weird with the PCM (computer) of the car.
This article might help: http://www.carterfueldelivery.com/fuelpump
Anyone I am completly lost as to what can cause this problem like this.
Just offhand I don’t know what the problem here is.
The fact that 12 volts is provided to the pump and fuel pressure is zero does not mean the pump is bad.
Bad ground connection or a flaw in the circuit that provides the 12 volts is a possibility.
It’s entirely possible to have 12 volts flowing through a wire, relay, wire connector, or what have you and the circuit is simply not strong enough to pass enough current (different than voltage) throug in order to operate the pump.
This could possibly be verifed by running a switched jumper wire directly to the pump and see if the problem reoccurs. This would not cure a faulty ground problem though.
The fuel pump is operated on a duty cycle. This means that the engine computer (PCM) turns the fuel pump on and off. The PCM exerts control, over the fuel pump, through the Fuel Pump Driver Module. This control varies the time, and load, on the fuel pump operation. I believe that your fuel pump is being powered too much (voltage) for too long (time). This might be at 12 volts, and constant. This would be 100% duty cycle, and this would be bad (overwork).
Have you direct wired 12 volts to the fuel pump? You should not.
You need a mechanic who can understand fuel pump duty operation, and is thoroughly familiar with scanning the PCM to check out the fuel pump control.
He will know/have access to the knowledge of what the inputs and outputs to the PCM are, and the values they should be. And, of it’s (the PCMs) proper control of the fuel pump.
While growing up my Dad restored a Mustang that went through about three starters a year. The common denominator was that he was buying the starters at the same place. Could this be your problem? How long did your original fuel pump last? You may have to buy a fuel pump from your local Ford dealership.
Second idea is that you may want to check into a recall that you didn’t get.
Third idea is trying a different octane of fuel or an entirely different station.
Also, I’m surprised that you aren’t getting any kind of fault codes from a professional diagnostic computer - even when the fuel pump is working properly.