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Thread: Strange starting issue

  1. #1
    Senior Member Denverdelorean's Avatar
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    Strange starting issue

    Hi everyone,

    I am having a strange issue with my car starting and running, I have stumped my mechanics and the guys at DMC so far.

    I can ge the car to start and idle on accumulator pressure alone. If I allow the fuel pump to prime the accumulator, then disconnect the fuel pump by pulling #7 fuse, the car wil crank over and start (it takes about 15 cranks to get it to turn over). It will then idle nicely until it runs out of fuel pressure and dies. If I try to start it with the fuel pump connected, it never catches. I assume this means it is getting too much fuel.

    Everything from the fuel pump to the fuel filter is new. John Hervey style in tank system. I get fuel from the cold start injector as I should. It's idles smoothly, so the distributor and warm up regulator must be working (based on my descriptions of the behavior to the guys at DMC california)

    Fuel lines are routed properly, Return line is clear. Rpm relay seems to be working. Otherwise the pump wouldn't come on. right?

    I'm stumped...

  2. #2
    Senior Member Bitsyncmaster's Avatar
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    My VIN:    03572

    Try to start it with the CSV connector pulled off. I only need the CSV in the summer time if my car sits for two weeks or more.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  3. #3
    Senior Member
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    My first thought was that it would be something wrong with the return line. Like the fuel can go down to the engine, but not back. You mentioned the return line was clear though... have you confirmed this somehow?

    EDIT: Well, I guess maybe if the two rubber hoses off the pump were swapped it could cause what you're seeing. If you sent fuel pressure down the wrong way during priming only, it would perhaps fill the accumulator but let you run the engine with the pump fuse removed.

    Can you snap a photo of the fuel pump area showing the ends of the hoses as they leave the pump boot and connect to the hardlines?
    Last edited by Jonathan; 07-15-2014 at 03:01 PM.


    Sept. 81, auto, black interior

  4. #4
    EFI DeLorean dmc6960's Avatar
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    Do you have a k-jet pressure gauge set? I'd be curious what the pressures are.

    I'd also second Dave M's suggestion about trying disconnecting the CSV.
    Jim Reeve
    DMC6960

    D-Status: - Getting some Spring exercise

  5. #5
    Senior Member Bitsyncmaster's Avatar
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    Quote Originally Posted by Jonathan View Post
    Well, I guess maybe if the two rubber hoses off the pump were swapped it could cause what you're seeing. If you sent fuel pressure down the wrong way during priming only, it would perhaps fill the accumulator but let you run the engine with the pump fuse removed.
    +1
    Now that thought makes sense.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  6. #6
    Senior Member Denverdelorean's Avatar
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    I'll try that, but we tried starting it with the CSV completely removed, so I think it is something else. crumbs.....

  7. #7
    Senior Member
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    Quote Originally Posted by Denverdelorean View Post
    I'll try that, but we tried starting it with the CSV completely removed, so I think it is something else. crumbs.....
    If you don't mind digging in there to get a photo of your hoses and hardlines, it could help or at least rule out one possibility. If you need help with how to access that area, just ask. You can sometimes get a decent view of the hardline connections peering through the passenger wheel well. You won't necessarily be able to tell where each hose originated, but it's a start.


    Sept. 81, auto, black interior

  8. #8
    Senior Member Denverdelorean's Avatar
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    Quote Originally Posted by Jonathan View Post
    If you don't mind digging in there to get a photo of your hoses and hardlines, it could help or at least rule out one possibility. If you need help with how to access that area, just ask. You can sometimes get a decent view of the hardline connections peering through the passenger wheel well. You won't necessarily be able to tell where each hose originated, but it's a start.
    I am not with the car at the moment, so I can't snap a picture, but the feed line is connected to the inboard hard line, and the return line is connected to the outboard hard line. Unless the hard lines are somehow swapped, i think they're right.

    the line from the fuel filter goes to the three o clock inlet on the fuel distributor from the drivers side of the engine bay over to the passenger side.

  9. #9
    Senior Member Bitsyncmaster's Avatar
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    Less effort to just pull the supply line off the distributor and put it in a bucket and run the pump.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  10. #10
    Senior Member Denverdelorean's Avatar
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    All the lines are plumbed properly. gas seems to get where it's supposed to but when i pull the injectors to check, they seem dry, so that leads me to believe that the distributor is not functioning as it should.

    I am in the process of pulling the entire fuel system off the top of the engine to send in for rebuilding.

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