So two days ago, my 22r carbie bucked then quit. After repeated pumping of the gas it restarted and ran the rest of the day. Since Oregon recently went to 10% eth, I changed all the fuel filters and guess what it bucked and stalled again, but wouldn't restart so I had to get a tow. I then disassembled the weber, blew out all the jets, checked the float and checked the fuel pump pressure (built to 2 to 3 psi from cranking which is within specs). It then restarted and ran fine for a few miles then would start to die. I "revived it three times during the 40 mile test trip by pumping it while it was still moving at highway speed in gear. It died again 1 mile from the house at a stop sign, but then restarted while being towed in gear. So I tried to blow out the gas lines with my 275 psi air pump because whenever it wouldn't start, the inline fuel filter (between the pump & the carb) would only be half full but nothing nasty came out. I drove it to work today (15 miles) without incident. During this ordeal I also filled up & added a can of seafoam to the tank. I also checked the plugs when it wouldn't restart and they were dry. SO WHAT CAN THIS BE??

Still have the mechanical fuel pump?

Yes, I tested pressure on the output side while cranking it and came up to 2-3 pounds which is in spec (2-4). I didn't thing you could have an intermittent problem with a mechanical pump. I made it home with just two blips, then it died in the driveway while idling but immediately restarted.

I had a similar problem with my 87 22r, it ended up being the mechanical fuel pump, there must have been a pin hole in the diaphram, because it would pump fuel like there wasnt a problem, then restarting is where it would give me trouble, try changing the fuel pump - they are cheap !

In the "old days" when I was a mechanic for Toyota, I changed hundreds of mechanical fuel pumps over a pinhole in the diaphram. The pumps almost always tested fine, but the intermittent issue was common for those with pinholes. The vehicles would run one minute, and not the next, and would appear to run out of gas. When the tow truck showed up , the vehicle would start right up and be driven to the dealership. Vaporlock was also a common issue (here in Texas, anyway). Some of the trucks had the lines rerouted by the owners for various reasons, and the routing usually put a line too close to the engine somewhere.

Well I checked the old fuel pump for volume and it seemed low so I changed it and the flow volume increased a lot, so that was a problem. But it died again any way. With the price of fuel I had been thinking about trying a Weber 32/36 instead of my 38 so I swapped that out and all seemed well for the day, then it died again. This time when I checked for spark from the coil wire there was none. So I replaced the coil wire and tried again with the number 4 plug wire pulled and it starts immedciately on three cyl??
So I turned it off, replaced the plug wire and it restarted so I drove it to get a new set of wires. I installed the coil wire in the parking lot and guess what - no spark! I go in and discuss ignition things with the parts guy who suggests the dist. pickup, coil, igniter or my MSD box. With that valuable bit of information I go back out and it starts. I went home and looked for loose wires and cleaned all grounds then spent Sunday taking test drives around town with no problems. The new weber seems smooth enough, with enough power when you get into it, but without the immediate power you get from the 38. I drove it to work today without problem, so I guess we'll see what happens. I was thinking of swapping the whole dist/ignition system for a DUI (the GM HEI style one piece/one wire systems). Any comment?

Thanks

Yep, you wouldn't be the first person to throw out their MSD setup on these. The GM setup might be the better bet, but I hope you still have your old stocker stuff laying around. Ain't cheap to find anymore.

At this point I still have all the stock ignition components. The MSD 6 actually splices into the original setup instead of replacing anything. So you end up with a tougher job trouble shooting.