Post by Hap on Apr 3, 2022 9:56:06 GMT -5
My M38 runs terrible, in fact, barely runs. But not long ago ran very well. I have had fuel problems and replaced most major fuel components, including the tank, pump, filters, and put in steel tubing under the Jeep. I discovered a vacuum leak associated with the windshield wipers, better, but still not running well. I replaced the condenser, points (.020”), rotor, and cap. Did not replace plugs or wires (shielded) but looked ok, and checked 1342 position. It actually starts OK, but immediately goes downhill to the point it won’t rev or if I get it to rev, backfires. I have rebuilt the carburetor because I had put in some ethanol gasoline, and most likely did more harm than good looking for possible gunk problems in the carb, completely missing problems probably associated with the vacuum leak. I have a 50/50 mix of leaded 110 and 87 octane (all non-ethanol). What I notice happening is that idle is relatively ok, but any additional gas pedal will stop any combustion, unless quick pumps and rpms will increase but it will quickly bog down. Perhaps this is the accelerator pump, but I don’t know which one is the accelerator pump. I read the end to end troubleshooting note and I feel reasonably sure that the problem is in the carb. I don’t have a vacuum gauge (not that it would do much good with how badly it runs) and I plan to purchase an electronic dwell/tach (pitched old ones years ago before I bought the Jeep). I put a timing scale on the engine, but I have read that the vacuum gage is a better method.
I’d like to ask if there are any suggestions on where to troubleshoot next before I spend a lot of money for a rebuilt carb? I attached a picture of the carb. I believe it is a “Carter YS / VS950 / YS637 for an M38-A1” (I wrote this down some time ago, but the carb does say YS)
thank you.
