High rpm limits???

Discussion in 'General Motoring' started by Bill, Oct 6, 2003.

  1. Bill

    Bill Guest

    I've got a 1990 Dodge Dakota with the 3.9 V6 in and have a real weird
    miss at high rpm. I checked and replaced the plugs,wires and coil and
    distributor but still it keeps showing up. I don't see it during
    normal driving but only if I put it in park and rev the engine up. I
    was trying to trace it to a cylinder by putting sparkplug test lights
    on three cylinders at a time but all I saw was a dimming of all three
    of the lights when the engine starts to miss almost like the entire
    ignition system is dampening. Does anyone know if there is some kind
    of rmp limiting programing in these engines?

    Bill
     
    Bill, Oct 6, 2003
    #1
  2. Bill

    Steve Guest

    This is a pre-Magnum 3.9, correct? Holley throttle-body fuel injection?
    I know the Magnums have rev limiting, but my knowledge of the pre-Magnum
    system is thin, at best.
     
    Steve, Oct 6, 2003
    #2
  3. Bill

    Bill Putney Guest

    Don't know if they did things like this in that era, but the late model
    LH's (and probably everything else) have a different rpm limit in
    neutral/park than when in gear. I believe it's 4000 rpm on my '99
    Concorde - certainly goes well above that when in gear - may be wheel
    speed vs. engine rpm limited, but not sure - never tested it and don't
    intend to, but it's at 110 or 118 or something like that according to
    the forums (to go along with tire speed ratings).

    Bill Putney
    (to reply by e-mail, replace the last letter of the alphabet in my
    address with "x")
     
    Bill Putney, Oct 7, 2003
    #3
  4. And why are you abusing your engine this way?

    Matt
     
    Matthew S. Whiting, Oct 7, 2003
    #4
  5. Bill

    Bill Guest

    Got pissed at poor idling and stomped it down in frustration. The
    place where it seems to cut out seems to be lower when its cold
    outside, not the engine itself just the ambient temp. This truck has
    all kinds of problems and I've been working on it for a year or so
    now. I take back what I said about not seeing it during normal
    driving, I was having problems again this morning and was really
    paying attention to the motor on the way to work and I think that the
    clank I'm feeling when I'm at highway speed with a constant gas pedal
    might be the miss. It's a brief moment where the motor seems to slack
    off like I've let off on the pedal and the trani has to slow down to
    match the engine speed.

    I did replace the ECM and it has gotten better but still no where
    close to normal.

    Bill
     
    Bill, Oct 7, 2003
    #5
  6. Bill

    Punch Guest

    hey bill I recommend you join the DML (dakota mailing list)
    you can locate them at dakota-truck.net, if its about the dakota they know.

    Punch
     
    Punch, Oct 8, 2003
    #6
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.