i own a 1979 CJ7, 258, I-6. i recently noticed that my CJ has lost a considerable amount of power. i added 33" tires and a lift last summer and everything(engine) seemed to run with enough power w/out gearing. Lately(past month or so) i have noticed a loss of power. the other day i went to start up the jeep and it was a hard-start. the jeep would start but it ran awfully rough and it seemed to have problems getting fuel to burn. i drove it less than a mile with considerabvle shaking and i couldn't get it to drive faster than 10mph. a few hours later i tried it again. it seemed to run fine. however when i took it about 5 miles down the road it crapped out on a steep hill...i had to climb the hill in 1st gear where i normally would climb it in 3rd or 2nd. also, i could not drive the car faster than 45mph...if i attempted to accelerate faster the jeep would shake and it seemed to misfire and deccelerate. anybody have similar problems...or can anyone tell me what could be wrong with my CJ 258 I-6???thanx
Sounds like a fuel supply problem. Replace your fuel filter and check your fuel pump for output and pressure. Any service manual will guide you on this test. If the output or pressure is low, check your supply lines and hoses for leaks. If you have a good supply of fuel to the carb, it may be in need of an overhaul(the jets may be plugged). Hope this helps, good luck!
Well, I think it is something to do with the carb. More specifically sounds maybe like the choke. Take out one of your spark plugs and see if there is any build-up that could be diagnosed. If there is change them out and find the problem. Is there any exhaust changes (i.e. black smoke?) Just a thought.