In Park or Neutral I can rev the stuff out of the 5.9L Magnum engine in the Demon to even almost 4K and snap my foot off the pedal and the RPM plummets but settles normally at about 850RPM just fine. However, when I do the same in gear (either holding the brake or moving forward), the instant I take my foot off of the pedal the RPM plummets but either chokes the engine so it settles at approx. 250RPM or kills the engine outright. If the engine just chokes to 250RPM, it will pretty quickly go back up to 850 where it should be, but still this shouldn't be happening, methinks?
I have checked all gears and it's only when the engine has load from the transmission (904). I think it might have to do with the transmission, but something tells me I'm an idiot for thinking that. Any insight?
I have cleaned the fuel system out well including rebuilding the carb and I have messed with the timing, setting it anywhere between 18° and 24°, just under where it becomes hard to turn over the engine cold. I have also tried setting the idle speed higher in order to overcome this issue. None of this has worked. I have a slight misfire at about 2400RPM, but not enough to kill the motor I think. I don't have any vacuum leaks, and my manifold vacuum is showing 15hg vacuum.
This is a newish problem. I have always had some trouble with my fuel system (attributed to issues with the fuel system which should now be taken care of), but never to this degree.
Any ideas of what else I could check? I find it suspicious that it only does this under load.
I have checked all gears and it's only when the engine has load from the transmission (904). I think it might have to do with the transmission, but something tells me I'm an idiot for thinking that. Any insight?
I have cleaned the fuel system out well including rebuilding the carb and I have messed with the timing, setting it anywhere between 18° and 24°, just under where it becomes hard to turn over the engine cold. I have also tried setting the idle speed higher in order to overcome this issue. None of this has worked. I have a slight misfire at about 2400RPM, but not enough to kill the motor I think. I don't have any vacuum leaks, and my manifold vacuum is showing 15hg vacuum.
This is a newish problem. I have always had some trouble with my fuel system (attributed to issues with the fuel system which should now be taken care of), but never to this degree.
Any ideas of what else I could check? I find it suspicious that it only does this under load.
