Mechanics

FUEL PUMP

1993 Ford Taurus

I have a 1993 Ford Taurus, 3.0l V-6, 130,000 miles. I just replaced the radiator because it was cracked. Upon completion of replacing it, the car would not start. The engine will turn over, but it will not start. It has a new battery and alternator (less than 3 months). I realized that when trying to start it, I did not hear the fuel pump initiate when the key was turned to the on position. I replaced the fuel pump, but the new pump does not initiate either. I have the new pump connected, with the fuel filter off. When the key is moved to the on position, it does not pump any fule through the lines. I am hesitant to believe it was a bad fuel pump that I purchased new. I think it is something not telling my fuel pump to work, some type of relay or control module. Any ideas?
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Jhchallis
May 12, 2007.




Initially, that was my concern. I figured since I had to remove that to install the radiator, there must be some sequence that it needed to be done to reset it or something. The pins are fine, I have removed and replaced it three times. At least now I know where the fuel pump relay is because that one was of my questions, I could not locate it! Any more suggestions other than replacing it?

Tiny
Jhchallis
May 13, 2007.
I would like to test first, it is getting pricey to get this thing running again. Battery, alternator, radiator, fuel pump.

Tiny
Jhchallis
May 13, 2007.
Thank you for help. I read on another post somewhere that I should tap the box with a wrench or something and it may work. Lo and behold, I tapped it with a screwdriver and it started working. The car started right up! Hopefully it will continue to run fine. If not, then I at least knwo the root cause of the problem. Thanks again for your help! : D
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Tiny
Jhchallis
May 13, 2007.
Me again. The car ran fine for about 3 days and now I cannot get it to run right. It will start, but runs really rough until it gets warm. Once the engine gets warm, it seems to run fine, except when you try to accelerate from a stop. I ran a code scanner on it because the check engine light came on and it came back with throttle positioning sensor errors, so I changed it to no avail. I ensured I put it in correctly. The code scanner also came back with an EGR Valve error, but I am not so sure the EGR valve will cause it to run like it is now. Any more suggestions? Should I go ahead and replace the CCRM or could you walk me through some test steps? Thanks again for your help.

Tiny
Jhchallis
May 23, 2007.
A bad EGR valve, if stuck open would make it idle rough. To check it, with the engine running, disconnect the vacuum hose from the EGR valve. Plug the hose and attach a hand operated vacuum pump to the valve. Apply 5-10 inches of vacuum. The engine should run rough or even stall. If it doesn't, or if it changes very little, replace the egr valve. Also inspect the vacuum hose for cracks or leaks before testing the valve.

Tiny
Rudpro
May 23, 2007.
OK, I have checked the EGR Valve, it is not the problem. I am having a hard time getting it to start, it is acting like it is flooding. Once it starts, it backfires a little. If I allow it to idle (when it will) and press on the peddle, it wants to die. It will also backfire at that point like it is getting too much fuel or something. I have replaced the distributer cap and rotor button. Next up is plugs and wires I think. Any more suggestions?

Tiny
Jhchallis
May 26, 2007.
You could check the fuel pressure regulator. It has 2 fuel lines going to it and a vacuum hose on top. Attach a fuel pressure gauge to the schrader valve. With the engine running, detach the vacuum hose from the regulator. The pressure should rise 8-12 psi. If not the regulator is bad. Also, if fuel is squirting out the regulator when you take the vacuum hose off, it's bad.

Tiny
Rudpro
May 26, 2007.
OK, replaced the fuel pressure regulator to no avail. Starts somewhat better and runs when warm. Acts like it is flooding when I give it gas from a stop and also on the highway when trying to hit passing gear. Anything else come to mind?

Tiny
Jhchallis
May 26, 2007.
Check the mass air flow sensor. Very gently tap it while engine is idling. If idle changes, sensor is bad. I'm not sure which type of sensor you have, but you might want to take it out and see if the resistors are dirty. You'll see 2 of them in the mouth of the sensor unit. If they look dirty, you can spray them with throttle cleaner. Be careful doing this, they are fragile. Do not touch them with anything, just spray them. If that doesn't help, I'd check the O2 sensors next.

Tiny
Rudpro
May 26, 2007.
No change in the idling when tapping the mass air flow sensor. I guess the oxygen sensors are next. Is there any special way to check it without just replacing it? I think if the O2 sensor was bad, wouldn't it shown on my code scanner? I have all clear during key on-engine off and engine running tests. My check engine light is no longer on. Man, am I getting frustrated!

Tiny
Jhchallis
May 27, 2007.

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