vforge
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- SE Pennsylvania
Hello,
Recently bought a 1953 M38A1. Not my first jeep as I also have a ‘63 CJ5. It didn’t really occur to me when I bought the M38A1 but it sounds like a diesel engine. It much noisier than my cj5. I checked the valves and they were adjusted properly. Compression numbers were ok, all between 110 and 125. (Not optimal but not awful).
It also has a weird problem of being difficult to start when it’s been sitting for a few days. The vacuum lines are rather crudely done so I’m wondering if that could be messing with it. I went to test the vacuum at the intake manifold and ran into some weird problem.
with the vacuum line disconnected and the vacuum gauge connected, the engine wanted to immediately start but wouldn’t run with considerable throttle. When it did finally run it sounded like only 2 cylinders were firing and it was smoking. I shut it off, reconnected the vacuum line and it started fine. While it was running, I disconnected the vacuum line and it immediately increased in RPM. I attached the vacuum gauge while it was running and it measured around 15 inHg, in the late timing. I advanced the timing while it was running both with and without the vacuum line attached. It seemed to sound better and the rpm’s increased as well. I don’t have a timing light yet so I can’t properly adjust it. (I will soon.) I still don’t quite understand the whole vacuum system and how it works. But does any of this seem right?
Recently bought a 1953 M38A1. Not my first jeep as I also have a ‘63 CJ5. It didn’t really occur to me when I bought the M38A1 but it sounds like a diesel engine. It much noisier than my cj5. I checked the valves and they were adjusted properly. Compression numbers were ok, all between 110 and 125. (Not optimal but not awful).
It also has a weird problem of being difficult to start when it’s been sitting for a few days. The vacuum lines are rather crudely done so I’m wondering if that could be messing with it. I went to test the vacuum at the intake manifold and ran into some weird problem.
with the vacuum line disconnected and the vacuum gauge connected, the engine wanted to immediately start but wouldn’t run with considerable throttle. When it did finally run it sounded like only 2 cylinders were firing and it was smoking. I shut it off, reconnected the vacuum line and it started fine. While it was running, I disconnected the vacuum line and it immediately increased in RPM. I attached the vacuum gauge while it was running and it measured around 15 inHg, in the late timing. I advanced the timing while it was running both with and without the vacuum line attached. It seemed to sound better and the rpm’s increased as well. I don’t have a timing light yet so I can’t properly adjust it. (I will soon.) I still don’t quite understand the whole vacuum system and how it works. But does any of this seem right?
