m37 runs for 20 minutes and dies

[ralphtile61]

my 1953 cdn m37 starts up great idles great then after 20 minutes stalls i cant start it back up until the engine cools down i have new points condenser rotor coil rebuilt carb fuel pump is 2 years old has good psi to carb ,gas tank is all cleaned out,i bought this truck 5 months ago i hooked up the original fuel filter so it back to stock what missin is the vent lines from distibuter to carb can anybody help thanks ralph.

[carter davidson]

The first questions that come to mind are, does the truck have a vented fuel cap and if so is it set correctly?

[ralphtile61]

The first questions that come to mind are, does the truck have a vented fuel cap and if so is it set correctly?

yes the cap is vented dont no what you mean by set correctly

[carter davidson]

The underside of the cap has open and closed marks, open is for normal over the road driving and closed is for deep water fording. Check and see if yours is set for open, allowing air to enter the tank as fuel is used. In the closed position the vacuum produced in the tank as fuel is withdrawn will limit or stop fuel flow if the vent lines are clogged.

[Charles Talbert]

Vent lines missing??

my 1953 cdn m37 starts up great idles great then after 20 minutes stalls i cant start it back up until the engine cools down i have new points condenser rotor coil rebuilt carb fuel pump is 2 years old has good psi to carb ,gas tank is all cleaned out,i bought this truck 5 months ago i hooked up the original fuel filter so it back to stock what missin is the vent lines from distibuter to carb can anybody help thanks ralph.

Vent lines to the distributor are extremely vital. Not having them in place will kill the coil due to overheating really fast. This could well be your stalling issue as what you have described is a classic symptom of a bad coil. Even though you installed a new coil, no venting will bring it a quick death.

[ralphtile61]

The underside of the cap has open and closed marks, open is for normal over the road driving and closed is for deep water fording. Check and see if yours is set for open, allowing air to enter the tank as fuel is used. In the closed position the vacuum produced in the tank as fuel is withdrawn will limit or stop fuel flow if the vent lines are clogged.

i dont have a gas cap that has open close on it ,the cap is just vented

[ralphtile61]

Vent lines to the distributor are extremely vital. Not having them in place will kill the coil due to overheating really fast. This could well be your stalling issue as what you have described is a classic symptom of a bad coil. Even though you installed a new coil, no venting will bring it a quick death.

thats what i was thinking if the distributor isnt vented when it gets hot it kills the coil thank you i have to order the vent lines

[Charles Talbert]

thats what i was thinking if the distributor isnt vented when it gets hot it kills the coil thank you i have to order the vent lines

They are nothing more than 3/16" brake line tubing available at any parts house, just bend them to fit. The critical part is to be sure you have the correct fittings that go in the carb elbow, without these there will be no forced air flow and the lines are useless. They are easy to make up or they may possibly still be in place on the elbow.

[ralphtile61]

They are nothing more than 3/16" brake line tubing available at any parts house, just bend them to fit. The critical part is to be sure you have the correct fittings that go in the carb elbow, without these there will be no forced air flow and the lines are useless. They are easy to make up or they may possibly still be in place on the elbow.

thank you for the tip with the brke lines ill pick them up today hopefully that will solve the problem