Willy's 1952 M38-A1 acting very odd....

[Ahines]

I've recently uncovered my grandfathers jeeps, an M38 and a 52 M38-A1. I'm currently working on the M38-A1 and this is what has happened. The jeep will start and run the first time I start it up without choke, and it will drive maybe a half mile, then cut off and never start again until I let it sit overnight...I have no idea what to do. My guess is a rusty gas tank, I've replaced the carb with the one from the M38 and blew out the gas line and syphened out the old gas and replaced with new but no change...thanks!

[wesk]

That symptom is typical for two different problems.

1-Fuel tank vent plugged up causing gas not to move from tank. Quick check, remove the gas cap and drive the jeep. If problem is alleviated clear the vent system. Depending on the year of your M38 and weather it has been modified the tank system either vents through a line to the air cleaner or thru a valve mounted on the top of the tank. Also check your cap. Some caps are venter all the time and some have a fording switch inside that allows you to close the vent system during fording operations.






This is the early M38A1 venting system. Make sure tube "E" is not plugged (it is the carb bowl vent) & make sure tube "K" from the top of the tank to the air cleaner is not plugged.

2-A week coil is very sensitive to heat buildup and will quit providing spark once it gets warm and will not spark again until it has time to cool down. If you are in a hot climate then the distributor vent system becomes very important to keeping the coil cool. In the schematic above make sure lines "P" and "EE" are not plugged. If your jeep has the fording valve make sure it is off (non-fording position).

You should not be able to swap carbs between your M38 which came with a L134 engine and your M38A1 which came with a F134 engine. The F134 (M38A1) carb has a much larger throttle bore size.


L134 engine used in the M38


F134 engine used in the M38A1 and the M170
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[Ahines]

I reallyyyy appreciate the response Wesk. Thanks for your time spent on it! I'm going to try the vent issue later today, I'll let you know what happens.