burning gas like crazy...

burley

New Member
Joined
May 31, 2005
Location
Wilmington
well about 3 months ago my girl got a cj-7 with a rebuilt jasper inline 6... it ran fine in a sense but the timing was set high because of idle issues... the previous owner said to just clean the carb and it would be fine... so i decided to do a full tune up on it and replace with a new carb. from advanced... well we got the new carb on and set the timing... started up and ran fine... then drove it about 1/32 of a mile and it died.. .kept flooding itself out... (the screws claim to be pre-set) well i noticed that carb had a leak in it so we took it off and her dad got a carb from some carb shop... put it on and the thing ran like a dream... only problem... the trip we always take used to burn 1/4 of a tank now burns a full tank of gas... ive tried readin up on diff. possibilites but havent been able to pin point it... if you can help me let me know as this thing is starting to become more of a hassle to drive then its worth and i dont wanna sell it... thanks in advance
 
Sure its not leaking fuel somewhere?Not sure if what you have has a manual fuel pump,if it does maybe the its leaking internally into the engine?If it has one check your oil :confused: Thats a place to start
 
def not leaking externally and the oil definately hasnt been thinned out by anything... thanks though... i know atleast one fellow cj owner has had this prob before.. hopefully?.... put a new fuel filter on during the tune up... now gets worse gas mileage... i dont understand this... i love my honda and toyota :driver:
 
If it is not leaking anywhere from tank to carb, and it there is no oil in the crank case, then the problem has to be still in the carb, maybe. Check the intake manifold for leaks. If it had to have timming advanced because of idle issues here may be an extream leak in the intake. Sucking more air, being able to use/burn more fuel. You should have black smoke out the exaust. Check the end of the exaust for a lot of black soot. The leak in the manifold could be up next to the head, or it could be where it is bolted to the exaust manifild. Jeep 258's are notorious for this.
ANother thought, is the jeep supposed to be fitted with the computor controlled 2bbl? could be bad computor, or could be wrong carb. Are the lines to the carb hooked up right? There should be a return line going back to the fuel tank for un-used fuel. You can also pull the top off of the carb to check and see what the float level is. If it is full the float is too high, if it drains out, where does it go? back into the fuel line(syphonage) or into the intake (trash in the jets) or bad needle valves.
Another thing to check are vacum lines, they mat be hooked up wrong, causeing it to hold open dumping fuel in even when it's not needed. Choke opening after it is warmed up? That something else that will use a lot of fuel.
Good news is, you must have done the tune up good, or you would be fouling plugs. You can also pull the plugs to see if all or just select ones are getting excessive fuel.
Hope something in the ramblings help
Chip
 
^^ All good advise, check that stuff first. A large vacuum leak will kill you. If that doesn't work, pull your jets and compare them to the jets of the orginal carb. I was using jets 10 steps higher on my 304 than what it came with and it ran way rich and burned twice as much fuel.
 
thanks a bunch.. ill look into all that above and also i wish i could compare to the original but had to give for a core deposit to advanced :(
 
Is it a factory carb? I thought during those years they were Carter carbs. I have had friends that took a couple of returns before they got one that worked. Alot of the rebuild companies don't really use the best kits. (cheap gaskets, bad jets and needles, etc.) i think holley still offers a 2bbl or a smaller 4bbl that work well. I dont think I have helped too much but there it is. There's also clifford performance that makes an intake that allows for holley and edelbrocks. Good luck.
 
I don't know anything about Jeeps, but any vehicle w/ a bad O2 sensor will burn a lot more fuel.


Matt
 
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