Antiquepem Posted February 1, 2019 Report Posted February 1, 2019 I have a 1951 Chrysler Windsor with the M6 transmission. The engine idles fine. When I'm driving and have to stop at a stop light the engine will stop after 15 to 30 seconds. I put the transmission in neutral and it immediately restarts. Several years ago I replaced the wiring harness from the coil to the carburetor, circuit breaker and resistor to all compents in the transmission. Any ideas about how to diagnose the problem. Quote
Doug&Deb Posted February 1, 2019 Report Posted February 1, 2019 Is the trans downshifting when you come to a stop? There’s an Imperial website that offers the factory troubleshooting manual for the M6 that you can download. If you follow the steps it’s easy to check the operation. My Coronet did the same thing and it turned out to be bad wiring to the trans. I replaced the trans harness and it solved my problem. Good luck. Quote
knuckleharley Posted February 1, 2019 Report Posted February 1, 2019 9 hours ago, Antiquepem said: I have a 1951 Chrysler Windsor with the M6 transmission. The engine idles fine. When I'm driving and have to stop at a stop light the engine will stop after 15 to 30 seconds. I put the transmission in neutral and it immediately restarts. Several years ago I replaced the wiring harness from the coil to the carburetor, circuit breaker and resistor to all compents in the transmission. Any ideas about how to diagnose the problem. Does the engine quit running if you put the trans in neutral immediately after stopping? Quote
Merle Coggins Posted February 1, 2019 Report Posted February 1, 2019 1 hour ago, knuckleharley said: Does the engine quit running if you put the trans in neutral immediately after stopping? Or with the clutch pedal depressed? Quote
Antiquepem Posted February 1, 2019 Author Report Posted February 1, 2019 No. I have no problems if I shift to neutral or depress the clutch. Quote
Antiquepem Posted February 1, 2019 Author Report Posted February 1, 2019 The transmission downshifts just fine. Quote
keithb7 Posted February 1, 2019 Report Posted February 1, 2019 (edited) Have you a shop manual to research the electrical circuit that is tied into the carb? When your gas pedal is mashed to the floor under a certain speed limit, the ignition sysyem coil is sent to ground. Interrupting engine spark momentarily. This allows the tranny to down shift. Removing the engine power releases the load on the tranny gears. The oil preasure behind the tranny shift piston is released. Allowing for a downshift. I’d look into this electric system tied to the carb. It’s suspect. It may be cutting coil power when its not supposed to. Stalling the engine. Just an idea. Dig in to lean more. Edited February 1, 2019 by keithb7 1 Quote
Hickory Posted February 2, 2019 Report Posted February 2, 2019 My vehicle did the same thing, a previous owner put the wrong fluid in the fluid drive torque converter. 1 Quote
keithb7 Posted February 2, 2019 Report Posted February 2, 2019 (edited) 49 minutes ago, Hickory said: My vehicle did the same thing, a previous owner put the wrong fluid in the fluid drive torque converter. Well thats interesting. I’m trying to think about what having the incorrect oil in the TC would do. Too heavy viscosity, TC slow to spin up? Increasing stall time? Once up to speed extra momentum initially. Reluctant to speed changes to slow down? Increased heat? Possibly caused by heavier oil that is less reluctant to change direction against the stator? Bonus lugging power on grades? Too light viscosity, TC spins up quicker? Less momentum? Quicker to slow down. I’m interested to hear how this would stall the engine. Experts please chime in! Edited February 2, 2019 by keithb7 Quote
kencombs Posted February 2, 2019 Report Posted February 2, 2019 12 hours ago, keithb7 said: Well thats interesting. I’m trying to think about what having the incorrect oil in the TC would do. Too heavy viscosity, TC slow to spin up? Increasing stall time? Once up to speed extra momentum initially. Reluctant to speed changes to slow down? Increased heat? Possibly caused by heavier oil that is less reluctant to change direction against the stator? Bonus lugging power on grades? Too light viscosity, TC spins up quicker? Less momentum? Quicker to slow down. I’m interested to hear how this would stall the engine. Experts please chime in! No expert here, but really heavy oil could create enough drag when in gear and not moving to lug the engine down and cause a stall. That could be more likely with winter temperature and an improperly low idle speed. After all, the oil slippage is what allows it to idle in gear without the clutch being disengaged. To the OP, have you assured that your idle speed is correct? That would be my first thought Quote
Antiquepem Posted February 3, 2019 Author Report Posted February 3, 2019 The idle speed is correct. 10w non detergent in the transmission. Correct fluid level. I do have the wiring diagram. Is there such a thing as a weak interrupter switch? Quote
Dodgeb4ya Posted February 3, 2019 Report Posted February 3, 2019 Is your car a Fluid-Matic standard Fluid Drive Coupling .....or is it the optional Fluid Torque Drive combined engine and torque converter shared oiling? Quote
normanpitkin Posted February 3, 2019 Report Posted February 3, 2019 dash pot in the carb not working properly? Quote
Frank Elder Posted February 3, 2019 Report Posted February 3, 2019 9 hours ago, normanpitkin said: dash pot in the carb not working properly? The dashpot has no effect on idle speed, it is to keep the engine from stalling when you slow down abruptly. Quote
Antiquepem Posted February 3, 2019 Author Report Posted February 3, 2019 Is there such a thing as a weak interrupter switch? I checked the oil level in transmission-3 pints capacity- added 1/2 pint. Quote
Dodgeb4ya Posted February 3, 2019 Report Posted February 3, 2019 Interrupter switches do fail.... Remove it and ohm it out to test it or follow the shop manual or online MyMopar films 1949 Vol. 2-12 The earlier M-5 single wire interrupters do fail more than the 1949-53 double wire M-6 switch. Reason they sell for $200.00 Quote
DJ194950 Posted February 3, 2019 Report Posted February 3, 2019 Found the MyMopar films on u-tube. https://www.youtube.com/watch?v=TLZcbFHIN1M DJ Quote
Antiquepem Posted February 3, 2019 Author Report Posted February 3, 2019 Thanks. I will go watch it now. Quote
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