Hard starting

[vforge]

My M38A1 has always been a little hard to start but recently got a lot worse. Over the weekend, the float got stuck open somehow and flooded the carb. I took it apart and checked the adjustment, everything else was fine. It's running and driving fine now besides a bit of rough idle at times. I tried adjusting the air mixture screw but it didn't seem to do anything. When I went to start it yesterday it took a lot of turning over. It seems it would try to start in the initial 2 seconds of turning over then nothing. It took 4 or 5 tries before it started sounding like it was really trying to start. And after another turn over or two it started. Carb is getting fuel. I need to check if it's making it into the combustion chamber and need to verify spark strength. But once it's running it seems to be fine. Any ideas?

 

[biscuitwhistler37]

M38A1 stalls after warming up

Hello, I have an M38A1 that my grandfather restored about 20 years ago. It has been stored in a garage for about the last 10-12 years. I'm trying to get it back up and running but have been having some problems with it after it warms up. The jeep will start and idle fine until it starts to warm...

www.steelsoldiers.com

We're fighting a similar battle here, lots of good info as to what your issue may be. Hope it helps

 

[vforge]

M38a1 vacuum at intake manifold

youtube.com

Vacuum gauge hooked up to the intake manifold.
it won’t start without a little bit of throttle. Barely idles with no throttle.

 

[vforge]

Going from throttle to no throttle

M38a1 no throttle

youtube.com

 

[biscuitwhistler37]

Have you verified spark and timing? When you went through the carb did you re-use the same gaskets or replace with new? That one sounds a bit rougher than the one I referred you to, almost like it's only firing on 3 cylinders, could just be the video. I would also do a compression test and make sure raw fuel didn't wash out any of the cylinders

 

[vforge]

Have you verified spark and timing? When you went through the carb did you re-use the same gaskets or replace with new? That one sounds a bit rougher than the one I referred you to, almost like it's only firing on 3 cylinders, could just be the video. I would also do a compression test and make sure raw fuel didn't wash out any of the cylinders

Carb was professionally rebuilt. I did not replace the main carb gasket when I opened it up to check the float. It was in good condition.

I checked the timing a bit ago and it was within spec. It did sound a bit better if I advanced the timing a little bit. I did a compression taste a month or 2 ago and it checked out ok.

I’m going to check the spark out. Maybe just a weak spark. I was already planning on converting to pointless ignition so I’ll try that next.