Fuel pump doesn't turn off

Asked by May 04, 2018 at 11:07 AM about the 1994 Mercury Sable

Question type: General

On my Mercury when I turn the key the fuel pump
comes on usually stays on for a minute then the
car starts now the fuel pump just stays on and on
doesn't turn off and won't start

1 Answer

4,300

Does this happens with the key in the ignition? Anytime the fuel pump stays running with the key on it's usually a stuck fuel pump relay or most likely a bad engine computer (PCM). If not, do the accessories work, radio, horn? If they work, check the ignition switch to see if it's shorting out and remaining ON, if it is OK, next check the fuel pump relay making sure that it is not stuck closed (there is only continuity across one set of contacts on the relay; if you have continuity across both, then its stuck closed). If your relay turns out to be good, see if the relay's power circuit is energized with the key turned off. If so, the problem can be a short in the relay control circuit, or a bad ECU. If the relay's circuit is not energized, then you're just going to have to start following the wire back from the pump to the relay, checking every so often to find out where power is having a short into the circuit. I copied these procedures from my Ford Shop Service Manual, revised October 1996. I hope the information is somehow helpful to you.

Your Answer:

Shortcuts

Mercury Sable Experts

  • #1
    JP1956
    Reputation
    830
  • #2
    Tom Demyan
    Reputation
    730
  • #3
    Guy Outland
    Reputation
    410
View All

Related Models For Sale

Used Ford Taurus
19 Great Deals out of 375 listings starting at $4,995
Used Honda Accord
33 Great Deals out of 1,640 listings starting at $2,671
Used Toyota Camry
29 Great Deals out of 2,122 listings starting at $2,995
Used Chevrolet Impala
16 Great Deals out of 985 listings starting at $2,994
Used Ford Explorer
21 Great Deals out of 1,793 listings starting at $4,490
Used Nissan Altima
42 Great Deals out of 1,230 listings starting at $2,800
Used Toyota Corolla
116 Great Deals out of 4,220 listings starting at $1,995
Used Ford F-150
123 Great Deals out of 11,298 listings starting at $369
Used Honda Civic
117 Great Deals out of 4,989 listings starting at $100
Used Lincoln Town Car
11 listings starting at $6,990

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.