Hello:
This is for a ’51 ½-ton 216. I need some help in identifying the cause of what I would describe as “lurching at very slow speed”. Let me first say I do know how to drive a manual transmission, so it’s not a case of having to learn that.
When the truck is warmed up, it idles just fine, very smoothly. When I shift into first gear or reverse and let out the clutch, the truck might move smoothly for a few feet at very low speed, but after a few seconds it begins lurching, and I have to give it gas to smooth it out. And not just a little gas, but maybe up to 7-10 mph (guessing). My expectation (perhaps incorrect), is that once the clutch is disengaged, on a level, smooth surface, the truck should be receiving enough fuel to roll, without depressing the gas pedal. If I’m backing out of a garage, it should be possible to ease out, but this truck wants more gas and therefore faster speed.
A possible clue: Years ago, for a reason I can’t remember, I disconnected the vacuum hose from the windshield wiper motor. This hose is now open to the air, and the truck won’t run if I reconnect it to the wiper motor. This may not be related, but the symptoms are very similar, in that covering the vacuum hose also cause lurching (because the engine is starving for air, I understand!).
Maybe I have the wrong expectation about this truck being able to roll in gear at idle speed, but it just seems like some adjustment is out of whack. Ideas or tests?
Last edited by Ol' Red; 10/06/2017 11:14 PM.
