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  1. #1

    Default 1988 6,2 hard to start

    Hey everyone.My truck got this strange behaviour a few weeks ago: When i stop the engine, and try to start again (hot or cold doesnīt matter) it takes about 5-15 seconds of cranking to start again. sometimes it wont start at all. but if i go down a hill and step off the clutch pedal it starts at once. I opened an injector pipe and cranked it and it got fuel immediately. So it seems like the cranking revs are to low, but they are the same as allways. So I wonder, do these fuelpumps have rpm-depending timing? As you know there is a black plastic box with three cables connected to it on the right side of the pump (the cars right side). Might that be it? I canīt think of any other possible reason for this behaviour, than wrong timing setting.

    I would also be happy if anyone could explain as much as possible about the electrics for the fuelsystem to me, for example what the switches with vacuumhoses connected to them, at the rear of the left valvecover does.
    An what te relay called "Optional Relay, beside the fuelpump relay does.

  2. #2


    Ok, there's not supposed to be a dumb question, only dumb answers. I'm going to ask, is this a diesel?

    The only thing that comes to my mind is, how is your battery capacity/voltage when cranking? I suppose if it's low you may not have enough power to open the fuel relay when cranking. But would have plenty available when you do the bump start.

  3. #3


    Yes itīs a diesel.But the problemis already solved. I figured it couldnīt be the timing, because the timing is only about a few degrees. So it had to be a fuel problem.And it was.The fuel i saw when i opened the injector pipe while cranking, was just fuel left in the pump. I followed the main cable from the battery and it was almost completely broken at one place. When voltage dropped while cranking it couldnīt push enouhg current through the main cable due to the higher resistance. Replaced the cable and back on track! Thanx anyway!

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