Unregistered users may browse the website, but in order to participate in the forums and view select pages (such as "Club Contacts" and "Classified Ads") a user account is required. Click HERE to email the webmaster and request a free account. The National DeSoto Club uses real names rather than pseudonyms. Notify the webmaster of your user name preference (Johnathon Doe vs. John Doe, etc.), preferred email address, and password request.
Hi all,
Does anyone have an idea or experienced a MOPAR flathead six that stalls under very hard braking from say 25 or 30 MPH? This car has a flathead six, a fluid coupling, and a m6 Trans. The dashpot magnet is working, however, I cannot tell if the inside of the carburetor part of the dashpot is working.
The fuel float level is correct.
Anyone with any ideas, I am all ears!
Thanks, James
Is your idle set to low?
Is your idle set to low?
Idle is correct. With an M6 if the idle is too high the thing will not shift. I am thinking it is in the electric dashpot unit inside the carb. The magnet is working.
The problem is that the electric dashpot, used with the M6 Trans only, is not adjustable.
I may turn up the idle a lot, even if the car will not shift and see if it still stalls on a hard stop. If it does not, then it has to be dashpot related. If it still stalls then it may be a float or main jet sloshing issue.
James
Is the car running all right otherwise? Is the gas fresh? What year is it. Bill
After a day of testing...we ruled out:
1. Carburetor float bowl or sloshing.
2. Electric Dash Pot - Anti-stall.
3. Carb switch.
4. Vacuum Booster.
5. Idle speed.
What it looks like is the Interrupter Circuit on the transmission kick-down. When I take off in high range and thereby can run up to 25 MPH without the governor killing the circuit and shifting...then I hit the brakes hard the car stops and the engine is running fine. If the car is allowed to shift into high range (2nd or 4th gear) and you hit the brakes hard, the engine stalls.
Something in the interrupter circuit on deceleration is causing the interrupter circuit to ground the coil longer that a split second.
I am wondering if there is an issue with the piston or spring in the trans as that rail is moves with is what touches the interrupter switch. Perhaps the forward momentum with hard braking is causing the piston and rail to push back to the rear too slow and hold the coil ground too long.
Any thoughts from M6 Trans experts welcome.
James
