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Thread: 91 Ford Crown Vic, no start condition, fuel pump stays running.

  1. #1

    Default 91 Ford Crown Vic, no start condition, fuel pump stays running.

    I have a no start condition on my 91 Ford Crown Vic.
    When I turn ignition key to on position the fuel pump runs but does not shut off. Before, when the ignition switch is in the on position, the fuel pump would prime for a second or two, go off
    and then the engine would start.
    I checked fuel pressure at the fuel rail, 40 psi. Have good spark to all spark plugs. Compression good. Checked relays too. All good.
    Also, Pulled codes with my OTC monitor 2000 and only got a code 81 for the EVP sensor.
    Is this a sign that the ecu or pcm is bad ,not shutting the fuel pump off after the initial prime? Any help is much appreciated. Thank you.

  2. #2
    Beater gonna beat sly's Avatar
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    Could be a sign. Check the relays first. ECA relay provides power to all the sensors. If that's not working right, nothing will work.

    Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
    rides: 88 MGM (SOLD), 93 Vic, 2000 Crown Vic, 2003 Expedition
    Quote Originally Posted by gadget73
    ... and it should all work like magic and unicorns and stuff.
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  3. #3
    BANNED! sxcpotatoes's Avatar
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    Could it be a failed fuel pump relay sticking and not turning off? There's another relay, I want to say the WOT A/C relay or something that's the same one you can yank and move over to test it. Someone should chime in soon to confirm or deny this.
    ,
    Slicktop '91 GS HO 4.30 rear. '82 Mark VI Tudor HO, '90 F-150 XLT, '62 project Heep, '89 Arizona Waggin' and '88 donor in PA, getting combined.

  4. #4
    I'm an air-conditioned gypsy gadget73's Avatar
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    If its not the pump relay, pull the ECM connector and check for water. The one time this happened to me was right after a nasty rain storm. FP stayed on, engine wouldn't start or it might sputter but not catch. Pulled the ECM plug and water ran out. After drying the connector and the ECM it ran fine and hasn't done it since.

    81 is either thermactor air diverter solenoid unplugged or the MAP sensor is not working like it should, depending on if its a stored code or not. no MAP would make it run bad but it will not cause the issue you're having.


    The other thing that keeps the fuel pump on is PIP signal from the distributor. This is also what drives the injectors. If for some reason the ECM sees signal on the PIP line, it might be keeping the fuel pump engaged. If that signal was some garbage that it couldn't process it may either not fire the injectors, or it might fire them randomly enough that it won't start. Try unplugging the ignition module to see if the fuel pump stops. If it does, my bet is on either the PIP is somehow flaked out in a way that its making random noise, or the TFI is goofy and doing the same. The pickup is inside the distributor and passes signal out through the TFI module. The signal is what makes it spark too.
    Last edited by gadget73; 06-12-2019 at 04:30 PM.

    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC SE, triple black (Timewarp) - poly front bushings, KYB struts and shocks, Holley SystemMax1 lower intake, SilverFox AOD valve body,

    1984 Lincoln Continental TurboDiesel - rolls coal

    Quote Originally Posted by phayzer5 View Post
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

  5. #5

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    Thank you gadget73. Problem fixed. Crown Vic running. Problem was with the TFI module. You were right . Looks like it was a flakey or messed up PIP signal going to the ecm.
    Also, maybe the ignition module plug going into the TFI was not making full contact with the contact pins in the TFI.
    I did what you wrote. I turned the key switch to the on position. The fuel pump kept running like before .
    With everything on I disconnected the ignition module plug from the TFI module, then the fuel pump stopped. I then reconnected the module plug back into the TFI module. Turned the ignition switch
    to the on position, the fuel pump then did the correct 1 to 2 second prime, then went off. Car started right up and got everything running.

  6. #6
    I'm an air-conditioned gypsy gadget73's Avatar
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    Awesome, love an easy fix.

    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC SE, triple black (Timewarp) - poly front bushings, KYB struts and shocks, Holley SystemMax1 lower intake, SilverFox AOD valve body,

    1984 Lincoln Continental TurboDiesel - rolls coal

    Quote Originally Posted by phayzer5 View Post
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

  7. #7

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    Update: Went to start the car this morning. The fuel pump stayed running. While I had the fuel pump running I pulled out the fuel pump relay and it shut it off. Put the relay back in, put key to on, fuel pump did the correct 1 - 2 second prime, then started the engine. Engine running fine. Problem I see is that when the car sits for a while and you go to start the engine the fuel pump runs continuosly
    causing the no start. Something keeps triggering the fuel pump to stay on after the car sits for a while. Maybe the ECM is the problem.

  8. #8
    Beater gonna beat sly's Avatar
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    Check the negative battery terminal as well. There should be a small black wire going to it. That's the ground for the ECM. Make sure that's got a good connection. Typically ECM is bad or good and no intermittent issues. You may also need to check the wire harnesses there at the brake booster. Those are known for getting weak connections after all the years. Take a pair of needle nose (or a small flat screwdriver) and try pinching the female connectors just a little.

    Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
    rides: 88 MGM (SOLD), 93 Vic, 2000 Crown Vic, 2003 Expedition
    Quote Originally Posted by gadget73
    ... and it should all work like magic and unicorns and stuff.
    Quote Originally Posted by dmccaig
    Overhead, some poor bastards are flying in airplanes.

  9. #9
    I'm an air-conditioned gypsy gadget73's Avatar
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    sure its not just the pump relay itself sticking? I've had relays die by staying on before, though that shouldn't affect it being able to start.

    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC SE, triple black (Timewarp) - poly front bushings, KYB struts and shocks, Holley SystemMax1 lower intake, SilverFox AOD valve body,

    1984 Lincoln Continental TurboDiesel - rolls coal

    Quote Originally Posted by phayzer5 View Post
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

  10. #10
    GMN Regular DerekTheGreat's Avatar
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    ..did you replace the TFI module and PIP sensor or have you just continued to disconnect and reconnect the harness?
    1985 LTD Crown Victoria - SOLD
    1988 Town Car Signature - Current Party Barge

  11. #11

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    Hello. This morning went to start the car up. Car sat overnight for about 10 hours. Key on, fuel pump primed then stopped. Priming this time, took 3 - 4 seconds. Car started right up.
    If the fuel pump take 3 - 4 seconds to complete the prime, it's possible the fuel pump is loosing its prime over a longer period of time.
    The fuel pump that is in the tank is a Carter fuel pump that I replaced 10 years ago. Maybe the fuel pump is getting weak.

  12. #12
    Beater gonna beat sly's Avatar
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    If it fires up after sitting for several hours, but not after sitting for less than an hour, I would place my bets on heat issue with the TFI module.

    Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
    rides: 88 MGM (SOLD), 93 Vic, 2000 Crown Vic, 2003 Expedition
    Quote Originally Posted by gadget73
    ... and it should all work like magic and unicorns and stuff.
    Quote Originally Posted by dmccaig
    Overhead, some poor bastards are flying in airplanes.

  13. #13

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    Sly: "If it fires up after sitting for several hours, but not after sitting for less than an hour, I would place my bets on heat issue with the TFI module."


    In reply to the previous post. The opposite is happening. I noticed that if the car sits for several hours like overnight ; the fuel pump is taking longer to prime. Somehow the pump is losing it's prime.

  14. #14
    Beater gonna beat sly's Avatar
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    Then it's probably the one-way valve in the fuel filter. Those are supposed to be changed every 10-20K miles. I know I'm bad about changing them myself.

    Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
    rides: 88 MGM (SOLD), 93 Vic, 2000 Crown Vic, 2003 Expedition
    Quote Originally Posted by gadget73
    ... and it should all work like magic and unicorns and stuff.
    Quote Originally Posted by dmccaig
    Overhead, some poor bastards are flying in airplanes.

  15. #15
    I'm an air-conditioned gypsy gadget73's Avatar
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    The pump prime cycle is purely time-based. It has nothing to do with how fast it ramps up pressure. The ECM has no way of knowing that anyway. It turns on for however many seconds the ECM commands it to.

    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC SE, triple black (Timewarp) - poly front bushings, KYB struts and shocks, Holley SystemMax1 lower intake, SilverFox AOD valve body,

    1984 Lincoln Continental TurboDiesel - rolls coal

    Quote Originally Posted by phayzer5 View Post
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

  16. #16
    GMN Regular DerekTheGreat's Avatar
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    What gadget said. If it cranks for an excessive amount of time (>3 seconds) before firing up then you could look into the fuel pressure regulator. That lives on the passenger side of engine under the upper intake on the fuel rail. We had an '89 Town Car which would sometimes fire right up and mostly need 3 seconds or longer to fire. Turned out it the fuel regulator was bad.

    Also, you never answered my question about the TFI module or PIP sensor.
    1985 LTD Crown Victoria - SOLD
    1988 Town Car Signature - Current Party Barge

  17. #17
    I'm an air-conditioned gypsy gadget73's Avatar
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    All of these will bleed down pressure after a while though. Even with everything new, 24 hours later its probably not holding any pressure in the line. I know mine never has. Doesn't stop it from starting fairly quickly even when its been sitting a good while. If it takes a long time to build pressure, thats either a weak pump or a clogged filter most of the time. If it starts hard even with normal fuel pressure, that points at a different problem. Lots of things can make it do that, but watching a fuel pressure gauge while its doing whatever it does will tell you if its a supply problem or not. If it comes up to more than 30psi during the prime period, you're probably fine there.

    still need to get into the engine and be lit off but if you've got solid pressure at the rail you're half good.

    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC SE, triple black (Timewarp) - poly front bushings, KYB struts and shocks, Holley SystemMax1 lower intake, SilverFox AOD valve body,

    1984 Lincoln Continental TurboDiesel - rolls coal

    Quote Originally Posted by phayzer5 View Post
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

  18. #18

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    My bad for not replying. Yes I did replace the TFI module.

  19. #19
    GMN Regular DerekTheGreat's Avatar
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    What about the PIP sensor? Those seem to be the real failure point.

    Ashley's old '89 did have good pressure at the rail, something like 33 or 36psi, I can't remember which as that was something like four years ago now and we were trying to figure something else out at that time. It still started hard, had a new fuel filter. Pump's status was unknown. We drove it like that until we sold it, but sometimes (like 1/13 times) it started like my '88- immediately. The other times, it cranked for over three seconds. When we sold it to LTDMan83, he said he replaced the FPR and all was well after that with starting.
    1985 LTD Crown Victoria - SOLD
    1988 Town Car Signature - Current Party Barge

  20. #20

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    The PIP was replaced too. I replaced that a few years ago. I have spark going to all of the cylinders.

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