[mfaerber]

Thank you in advance for reading this!

1998 Taurus SE Wagon... (V6 3L DOHC)

Yesterday, after driving the wagon for about 20 minutes in the hot city, the engine began to stutter. The driver immediately pulled over and by the time she got into the grass, the engine stopped. Just before this happened the engine was running too hot (not in the red though) - this is probably due to another problem it has been having where it frequently purges coolant when parked. I have since added more and replaced the cap which looked damaged on the inside (the overflow tank is new). Once pulled over, we could not start the car again, the engine would not turn over, but would try... violently.

After a good bit of googling, it fits the description of a failing fuel pump. I bought a fuel pressure gauge and followed the directions. With the key in the ON position, just before engine start, the gauge displayed a constant 15psi (I tried this twice). I turned the key to crank the engine (and it did after a couple spurts). At this point, the gauge displayed 30psi and stayed at 30 for a couple minutes.

The battery is new. The fuel pressure regulator is new. The spark plugs are a year or two old. I have a nice scan tool, but it is not detecting any error codes or pending error codes. I admit that I frequently allow the fuel level to go well below a quarter of a tank, which I now know is not good for the pump...

What do you all think?

Thanks!

 

[shoz123]

You need to get the cooling system fixed. Aluminum motors and the gage in the hot zone are a bad combo. The tank may need replacing if the threads have been cross threaded. Otherwise it may just need a new cap. The system will not work correctly if it cannot buildup pressure.

That being said you should have close to 40 lbs when cycling the key and the engine off for fuel pressure, 35 lbs when idling and 30 lbs at high vacuum.

 

[mfaerber]

Thank you shoz.

I bought a fuel pump + assembly and I'm going to replace it today. I'm a google-expert, so this will take a while.

Even if the fuel pump isn't the main problem, I'll feel good knowing that I won't have to worry about it in the future.

 

[shoz123]

The ring that holds the fuel pump module in can be a bugger to get out sometimes. They sell new ones at the dealership. Sometimes it is just easier to cut the old one out.

 

[mfaerber]

More testing:

If there is no pressure in the lines to begin with, and I turn the key to ON/EngineOFF, then the PSI will only ever (slowly) climb to 15psi. Only after repeated turns from OFF/OFF to ON/EngineOFF does the pressure slowly climb to 30-35psi. In either case, the pressure holds once the car is off.

When I crank the engine (there is still a tiny bit of stuttering before starting) the PSI holds at 30-35. When I put the pedal to the floor, by the time the RPMs climb to 3.5, the engine begins to stutter and I'm afraid to push it any further.

When the car left me stranded yesterday, the RPMs were probably around 2.5-3.

 

[mfaerber]

FYI:

My oil pressure switch is leaking oil through the body of the switch (i'm pretty sure that's what it is, see this thread).

 

[mfaerber]

I replaced the fuel filter (was dented/rusted/old looking). Now I'm going to replace the oil pressure sender while I have the car jacked up.

After replacing the fuel filter I used the fuel pressure tester and the results were different from before. Now there is around 20psi even when the car is completely OFF. I stood there holding down the tester's pressure relief valve - and watched fuel siphon into a gas can - for a while and each time the PSI continued to stay around 20psi afterwards. Also different is that the tester's needle moves much faster when I turn the car and crank the engine. I THINK the engine might be cranking better than before.

thoughts?

 

[mfaerber]

I replaced the oil pressure sender - looks like that stopped the leak.