onewhitezj
07-24-2009, 08:15 PM
heres what I have
1973 Jeep CJ5, Inline 6 4.2l, Motorcraft carb, RV cam, header otherwise stock.
Went wheelin the other day, got into a rocky creek bed and it started running really rough, and progressed to running only at higher rpm's only, idle wasnt even an option, and higher rpms were even sketchy, still are.
went home, checked for vacume leaks, found a few, seemed to help a little but still no idle, it just dies.
checked fuel, it appears to be getting fuel, new fuel filter, float bowl is full of fuel all looks good in the carb, no gunk...
Jeep will run at higher rpms, but only marginally, will run good, then start studdering out, if I jab the rpms up it will pick up and run good for a few second and start stuttering again.
If I unhook the vacume advance hose, plug it and manually adjust the vacume advance it helps a lot, it doesnt run 100%, still varies rpms, and I have to make small adjustments but can get it to run and stay running. My thought is that the vacume canister (or whatever its called), the diaphram inside it broke? Not sure if there is one in there but would assume thats how it works, vacume sucks the diaphram and controls the timing advance correct? If I increase or decrease the rpms the vacume advance never moves by itself. The vacume hose is comming out of the manifold under the carb gets vacume through it, I can feel it.
The Jeep ran fine before the trip, and now runs like crud...am I missing something?
Can I buy a vacume canister for the distributor, or do I have to replace the whole thing? There is a very slight, maybe a few thousandths play in the distributor shaft as well, not sure what tolerances there are for movement..none at all I would assume....
1973 Jeep CJ5, Inline 6 4.2l, Motorcraft carb, RV cam, header otherwise stock.
Went wheelin the other day, got into a rocky creek bed and it started running really rough, and progressed to running only at higher rpm's only, idle wasnt even an option, and higher rpms were even sketchy, still are.
went home, checked for vacume leaks, found a few, seemed to help a little but still no idle, it just dies.
checked fuel, it appears to be getting fuel, new fuel filter, float bowl is full of fuel all looks good in the carb, no gunk...
Jeep will run at higher rpms, but only marginally, will run good, then start studdering out, if I jab the rpms up it will pick up and run good for a few second and start stuttering again.
If I unhook the vacume advance hose, plug it and manually adjust the vacume advance it helps a lot, it doesnt run 100%, still varies rpms, and I have to make small adjustments but can get it to run and stay running. My thought is that the vacume canister (or whatever its called), the diaphram inside it broke? Not sure if there is one in there but would assume thats how it works, vacume sucks the diaphram and controls the timing advance correct? If I increase or decrease the rpms the vacume advance never moves by itself. The vacume hose is comming out of the manifold under the carb gets vacume through it, I can feel it.
The Jeep ran fine before the trip, and now runs like crud...am I missing something?
Can I buy a vacume canister for the distributor, or do I have to replace the whole thing? There is a very slight, maybe a few thousandths play in the distributor shaft as well, not sure what tolerances there are for movement..none at all I would assume....