I have an xj that we put on a 1948 Ford truck body. We changed it over to carb. We added a electric fuel pump filter and put on a 32/36 carb. Runs great and no real issues until lately… if we let it sit we have to prime the carb with a squirt can to get it started. But after that it’s good for all day. Start stop restart no issues. If it sits overnight it will not start until we prime it again with squirt can.
I put on a one way check after the in line pump tho king it was bleeding back into the tank. Nothing changed. Changed the in line filter out thinking it may have a crack on it nothing changed. Unhooked the line at the carb, turn key and it’s pumping plenty of fuel up to carb. Checked screen on carb .. clean… pulled jets out and no blockage.. b12 the whole carb to clean it out. Runs great, unless it sits overnight. Then won’t start til it’s primed again. Fuel bowl vent tube capped off so gas shouldn’t be evaporating that fast… I’m down to either the accelerator pump diiaphram may be bad? Or what??? Like I said after starting it runs great. Just not pulling gas in to start it up.

also now it falls on its face with full throttle. But as long as you don’t floor it runs great. Thai just started..
any suggestions??

 

Neat truck!! My first vehicle was a 52 Ford F100 with a Flathead V8 and a crashbox 4 speed.
I'm thinking there is fuel evaporating out of the bowl or leaking out overnight.

 

You don't really have a problem. You just posted this so you could brag about your cool truck.

Nice!

I'm with Cruiser. It's leaking. It's evaporating before you see it the next morning. When you park it for the night, put some paper towels around it to see if you can capture some trace of it leaking.

 

brand and specs thanks lookin to run carb on 99...
should the carb vents not be open?

 

I agree, the bowl is getting dry. And cool truck.

My first experience with that vintage was in the woods. There was an area going to be designated roadless and one of those trucks was in it. Went in with mhy Bronco and a trailer and tripod and pulled the motor and tranny. I bored it 5/16" over, dual carbs and stuffed in it a flat fender Jeep. incredible torque out of that 300 cu in engine. Hard to keep cool though

 

it is evaporating out but you cranking it should be refilling the bowl fairly quickly. try turning the key on and off a few times or putting it in run and not start for a couple seconds to fill the bowl.

and since its falling on its face at acceleration now, check you accelerator pump, maybe a torn diaphragm?

why did you pick a 32/36 for your "truck"? its kind of small for the 4.0, not jet wise but bore wise. it will run but you are losing performance choking the engine down like that. i changed the weber 34 on my 87 wrangler to a 32/36 and was not impressed, other than it started and ran smoother. i came from weber 32/36 on my small older bmws so i had lots of time on them. i ended up going to a holley four barrel from a 60s mustang and an offenhauser intake and that was the greatest increase in gas mileage and performance. my wrangler would smoke the tires all the way across the intersection with that holley on it and having the two main barrels smaller than the rears gave it great mileage if you weren't hot rodding it everywhere.

i believe that old carb was a 390cfm but maybe it was a 420 or 450. i cannot remember but if you get tired of that little weber, look for a small four barrel holley or whatever brand carb you are comfortable with but don't get one of those holley/motorcraft two barrels because your gas mileage will decrease and no large power gain.

 

I don’t see anything from it around the carb, but I’ll put some towels around and double check. Thanks

 

I have a electric fuel pump you would think it would fill the bowl up when you turn the key, but even with pumping the accelerator still will not start unless you squirt a shot of gas in carb..

 

collins brothers Jeep in tx can hook you up they do them all the time. But it’s a knock off webber 32 36 carb. I’ll get the part numbers for you later tonight.

 

I bet that was a fun truck. This one seems like it will be fun. Left all the running gear stock so easy to work on and get parts. Have to manually shift for now but will run 100 on highway. And still has 4x4.

 

great information. When we started this didn’t know much about the Jeep and switching from fuel injection to carb this was what was suggested by Collin brothers in tx. They sold the manifold, distributor and carb to us and that’s where we started. But I’m liking your plan better. Maybe and upgrade coming soon.
As far as turning the key the pump comes on. But bowl doesn’t seem to be getting gas. I can pump the pedal 5 or 6 times and nothing. But once I squirt the carb starts and runs great and will start the rest of the day fine. I would think the bowl would fill when the pump comes on. I pulled the line to the carb, turned key and it’s getting gas. 3.5 gph. I ordered a accelerator pump diaphragm thinking that maybe the issue.

 

so once you turn the key and the pump comes on, you push the throttle and nothing squirts out of the jets until after the engine is started with starter fluid.. hmm, your needle and seat seem to be sticking and not allowing fuel in but its funny it starts working after the starter fluid. did you guys do any adjusting on the carb when you installed it? i wonder if its got some junk in the bowl and its keeping the needle from moving easily until the engines kicks over a bit and knocks the needle loose? or if the needle hanger is not seated on the float hook properly?

i would undo the carb top screws and lift the top off and check it out. wiggle the floats up and down and make sure the needle moves easily. i would do it first thing before starting though so i could see what is going on in there in the setting where you are having trouble. your gasket will be fine. and since they sold you a weber clone, that could easily be your trouble. sometimes you can get a good real deal weber on ebay for cheap. you can get a weber 38 also. that will be a huge increase over that 32/26 and will sit on the stuff where the 32/36 sits. you will have to mess with the linkage though.

when it is running, with the filter off the carb, do you see little squirts of fuel when you look down the throat and pull the gas a little? you should but if you don't, that's a sure sign your accelerator pump diagram is bad.

http://www.redlineweber.com/html/Tec..._breakdown.htm

that is your carb in an exploded view diagram, that link to redline weber

 

also, how did you guys tune that carb to the engine? the best way will be to buy a vacuum gage from you local auto parts place and google how to use it for setting the carburetor and timing, if its adjustable on your engine.

i went from so-so running to immediate crank and perfect idle with great gas mileage using a 15 or 18 dollar vacuum gage from oriellys on my wrangler with that four barrel. and i felt i knew how to tune a carb by ear and driving since i grew up having a few carb'd vehicles. (65 mustang, 71 and 70 karmann ghia, many vw bugs, a 76 regal, and a 79 chevy truck). that vacuum gage showed me how wrong i was

 

Hey cruiser, makes me wanna rip out the stroker and put it in the 52 Chevy, haha!

 

Find a rusted or wrecked 2wd XJ and transplant the engine and trans into the Chevy. Keep the fuel injection!!