1981 Jeep CJ7 medic can you help me?

Thanks a lot medic, I really appreciate your help. I'll take pics and try to send them tomarrow. I timed it with a timing light to 8 degrees btdc and it fires right up even near zero here in Michigan. After about 20 minutes or so it just dies like the fuel is being slowly shut off. If I'm driving I pull over and sometimes it just idles and I wait a few minutes and it'll run again. It usually acts up going up a hill. But it'll quit in front of the shop or in the shop, too. When I replaced the first rusty tank I managed to get the new tank contaminated and removed it 5 times to drain and blow out little rocks in there. I did manage to repair the original fuel/vapor separator but bought a new one from a 440 mopar or 426 mopar as it had the same number of pipes going in and out. I plan to take the tank out (6th time) and fill it up with hot water and really clean it out and blow the lines out and make sure the two other fuel system parts are clean. The jeep now is just one pipe from the fuel sending unit on the tank to the fuel pump and up and over the top of the engine to the fuel filter which has a 3d leg which is routed back under the engine and clamped next to the intake line all the way back to the tank area where it goes to the roll over valve, from there to the fuel/vapor separator and then into 2 vent lines on the driver side top of the fuel tank. It acts like some rock or something is getting wedged into something and blocking the fuel. Sometimes it will gradually die and then pick right back up again and go only to die again. The vacuum lines are all goobered and when I got it the vacuum lines were not hooked to anything. I've played with them trying various combinations but there does not seem to be a charcoal canister, cto, there is an insert into the manifold forward of the carb that has 2 plastic tubes going straight up so I hooked some vacuum lines up to that thing and one from the distributor to the carb. Pcv to a large brass fitting just above the egr valve in the intake manifold. The other hose from that brass fitting goes to the brake booster. I have the vacuum line from the egr valve going into that funny 2 prong thingy on the intak manifold. And I have another vacuum line from the carb going into that 2 prong thinga majig.. Thought I'd check the ground wires to the engine block and look at the coil ground wire tomarrow as well as the prep of the fuel system and see what happens. Got the jeep in December and its still not a runner. Thanks again for your insight since I shouldn't be allowed near tools.

Hi medic,
I replaced the spark plugs, gapped to.035, replaced the points and condenser and cap and rotor. The ship came with that old distributor and a bbd carb out of a 1979 dodge d100 pickup with a 318 in it. The carb says manufactured by carter carburetor st Louis. 1A 0-2425. I got a carb kit and the reason it doesn't run is probably because I overhauled the carb myself. Did find a rebuilt unit on the web and its on its way in a week or so. The dwell is about 34 degress, I need to get new spark plug wires but I' m just trying to get it running. Last week I drove it from my house to Whitehall for a basketball game and back to my house the all the way to Manistee and back to my house with no problems. That was 150 miles or so. It has a 5 speed and the thing left Toledo with a 4 banger and 4 speed so some owner replace it with an engine dated 11 1982. Its an 81 cj7. All I do is hit the starter and it fires right up so maybe I screwed the carb up somehow. I went back and revisited the carb several times and adjusted it according to the rebuild kit and the Haynes manual.

And replaced the fuel pump.

At one point I unhooked the fuel line and cranked the engine and got no fuel. I hooked up a vacuum pump and got no fuel and left it on the fender sucking 25 hg's or whatever they are for over an hour and no fuel. Took the tank down and found little rocks and debris in there, last time I did the fuel check I was able to fill a mason jar by cranking the engine and filled the vacuum pump bottle very quickly. On both lines on either side of the engine. Changed fuel filters and blew them out and it was clean everytime. Still contamination when I blew out the lines without removing the tank a few days ago so I'm convinced there is more contamination in the system. Blew the lines out into a plastic container and found small sandy type grit and small pebbles.

Hi medic,
thanks for the pics, I see right away my fuel line system does not match your first schematic. Mine has the return steel tube next to the pickup line blocked with a rubber cap and steel band and they routed the return fuel back to the roll over valve, then to the fuel/vapor separator and then down to the 2 small vent hoses on top left of drivers side tank.
Since I, too, have no carbon canister please tell me how to route the vent line from the fuel vapor separator up to the front. I will go ahead and hook the return line to the second pipe on the sender. Thanks a lot, that may be the problem.

I just looked at your green tube in the second picture and my guys removed that as well, so I will just go to the hardware store and buy enough to stretch from the roll over valve to the firewall like you did, and I already have a clear plastic filter like yours with the pipe cut off like you did. I will start on this project as soon as I do some snow throwing this morning, thanks again.

I'm too dumb to post. Took pictures of the jeep engine but don't know how to send them, I'm not computer literate. They weren't very good, awful dark in the shop. Did get the tank out for the 6th time and blew out the lines again. Went to the parts store and got 25 feet of hose for the green hose. Bunch of clamps and zip ties. Found my clear in line filter like yours and will mount that tomarrow in the same place you did, thanks a lot. The Haynes manual didn't show that at all so I had no clue, the last mechanic must've removed it when he removed the charcoal canister. Have a new top strap coming for the skid plate and as soon as it arrives i'll put the tank back in. I put it on the bench and blew it out and rocked it back and forth and got most if not all the contaminants out. I repositioned the fuel filter above the engine like you have yours, thankyou.

Thanks a lot medic
really like the offy manifold and 4 bbl trick. Maybe next winter I'll do that. Too late, I already bought the new steel 15 gal tank and skid plate but that can be changed, too. Thanks.
Plan to wait for the new middle tank strap to come and then put it back together and see if it still dies, then if it does I still have the rebuilt carb coming between 18-23 feb. Catch up with you later

Roger, thanks a bunch. Next day or two will tell the tale.

Hi cj medevac,
got the filter attached to the firewall and put the tank back in today around 4ish hit the starter and no fuel to the carb. Put a mason jar under the steel line to the carb and ran a short hose into the jar and cranked:no fuel. I made sure not to allow rocks into the lines by duct taping the ends of all of them until it was time to hook up. This will be tank removal # 7. I blew all the lines out except the ones to the roll over/fuel vapor separator and hook my little vacuum pump up to those before I hooked up. I didn't want to blow some diaphragm somewhere. In the morning i'll start again and remove the tank and this time i'll take the sending unit out and inspect it. Didn't do that this time. I'm sure the line to the pump is hooked correct and the return line from the little pipe on the filter goes back next to the one on the sending unit. Then I made up one from the roll over valve up to the firewall.