Engine Help with fuel issue and line

[Brad88yj]

I recently purchased a 1983 CJ7 with a 4.2L the motor was in pieces in the rear. I have gotten to the point it runs. The previous owner did a nutter bypass and installed a HEI distributor and 2 barrel carb without the electronics in the rear. The issue I am having is I believe the carburetor is getting to much fuel. It idles fine drives good but when I turn the engine off there's still a steady drip of fuel dumping into the carb. If you look at the picture attached I didnt know what to do with these two ports or vacuum connectors. I just capped them. Any suggestions would be greatly appreciated.

 

[Armyvet25]

rebuild your carb, a steady drip of fuel after shutoff as you state is a out of adjustment float(maybe even punctured) and possibly the needle float seat is worn or dirty and not shuting off the fuel supply, think of it like a toilet that keeps running.

 

[Armyvet25]

also, any vacuums above the linkage are not considered true vacuums, capping is good, the lower vacuum ports will cause issues if left open, large should go to brake booster if so equipped, another to the distributor advance if so equipped, the rest not needed in a nutter bypass unless some vacuum is needed for vent blend doors, but most are mechanical.

 

[Brad88yj]

After doing more research I see the oe fuel filter has two lines out the back. I think the reason my carb is getting such high amount of gas is I don’t see anything going to the return line to tank. Maybe this is causing excessive fuel to flood the carb.

 

[Armyvet25]

After doing more research I see the oe fuel filter has two lines out the back. I think the reason my carb is getting such high amount of gas is I don’t see anything going to the return line to tank. Maybe this is causing excessive fuel to flood the carb.

Factory fuel pump on a CJ should not have enough power to overcome the carburetor and flood the engine. Add the return line but I think this will not alleviate the issue, in fact, if the filter has 2 rear lines and has a check valve that's supposed to allow return fuel from excess pressure(ie fuel percolation) and doesn't go to the tank, then if there was excess pressure it would just dump it on the ground out the return on the filter. I think you're grabbing for a life line to prevent the inevitable rebuild of the carb. But first things first, make sure your fuel lines are routed properly, feed and return, then recheck, if still dripping...rebuild the carb! Also, you never mentioned if it has the mechanical fuel pump or an aftermarket electric. Good luck.

 

[Brad88yj]

Factory fuel pump on a CJ should not have enough power to overcome the carburetor and flood the engine. Add the return line but I think this will not alleviate the issue, in fact, if the filter has 2 rear lines and has a check valve that's supposed to allow return fuel from excess pressure(ie fuel percolation) and doesn't go to the tank, then if there was excess pressure it would just dump it on the ground out the return on the filter. I think you're grabbing for a life line to prevent the inevitable rebuild of the carb. But first things first, make sure your fuel lines are routed properly, feed and return, then recheck, if still dripping...rebuild the carb! Also, you never mentioned if it has the mechanical fuel pump or an aftermarket electric. Good luck.

It’s mechanical and I had put two clear filters in between pump and carb to see if I was getting fuel and see if I was getting particles. Literally when I turn keep on it fills those two solid and still good spray from the jets. Soon as I shut off Jeep it wants to blow fuel into carb and also out those ports I circled if I take the caps off

 

[jsherman@brockmanheating.]

I recently purchased a 1983 CJ7 with a 4.2L the motor was in pieces in the rear. I have gotten to the point it runs. The previous owner did a nutter bypass and installed a HEI distributor and 2 barrel carb without the electronics in the rear. The issue I am having is I believe the carburetor is getting to much fuel. It idles fine drives good but when I turn the engine off there's still a steady drip of fuel dumping into the carb. If you look at the picture attached I didnt know what to do with these two ports or vacuum connectors. I just capped them. Any suggestions would be greatly appreciated.
View attachment 76560

I was told to leave those vents open. It ran way better. i did not have the fuel issue that i know of .

 

[Brad88yj]

I’ll try that as well. I never tested them to see if they were vacuum just capped them

 

[Armyvet25]

First off, they are are vacuum, venturi vacuum-low pressure created from air rushing into the carb, not full manifold vacuum though, second, your ignoring the carb issue hoping it goes away if you do something else, sorry, can't help you anymore. Good luck

 

[Brad88yj]

First off, they are are vacuum, venturi vacuum-low pressure created from air rushing into the carb, not full manifold vacuum though, second, your ignoring the carb issue hoping it goes away if you do something else, sorry, can't help you anymore. Good luck

Not ignoring the carb at all but since it was brand new out of the box that’s the last place I will check I would hope a brand new carb wouldn’t need rebuilding. I got home I put the original fuel filter back in ram one of the lines down to the return line then hooked the Venturi ports back up to the air cleaner and all is working fine with no more drips or issues with carburetor. Thanks for everyone’s help!

 

[Super8mm]

Not ignoring the carb at all but since it was brand new out of the box that’s the last place I will check I would hope a brand new carb wouldn’t need rebuilding. I got home I put the original fuel filter back in ram one of the lines down to the return line then hooked the Venturi ports back up to the air cleaner and all is working fine with no more drips or issues with carburetor. Thanks for everyone’s help!

I had a friend that bought a new 4 bbl but couldn't get it to run right and as it was out of warranty i gave him $20 for it. I tired it on my J2000 and had the same problem and the third time it took it off it dawned on me that there was no fuel in the float bowl so I poured some gas in it and it just drained out the bottom. one of the lead plugs was missing from the bottom so I took a split shot out of my tackle box and drove it in and problem solved.

So new does not mean there is not a problem with it.

 

[Armyvet25]

Most likey the venturi vacuums which draw the fuel in, since not hooked up may have caused the problem, didn't know it was new, wasn't stated in first post, nor whether it was installed new recently, sat a while etc. The fuel pump only delivers the fuel to the carb and shuts off delivery when the float reaches it's level, after started the venturi/system within the carb creates the low pressure to draw the fuel in, then the pump will continue to keep the fuel level in the carb, so it may have been caused by all the vacuum lines blocked off, but haven't heard f it forcing fuel after shut off before.