My buddy has an 84 with a 22R, one of those knock off "weber" 34/34 carbs on it. It's had a flat spot in it when cold ever since he put that POS carb on it, but his distributor was also not quite right either. The vacuum advance didn't move smoothly and he had oil in the vac. diaphram. So, we put a new distributor in it timed to spec and it runs HORRIBLY now. Truck has to be all the way warmed up for it to be driveable. Otherwise, it hits its old flat spot, and will almost stall. He's spent hours chasing his tail advancing timing, adjusting idle mixture, swapping vacuum lines around to no avail. The only thing he's found is that it runs better with the vacuum retard hooked up than disconnected like his carb's instructions said to do.

Any ideas? It's his DD and I'd like to help him out but I'm out of ideas.

 

I had a stock 84 4Runner with a 22R that had the same problem, no matter what i did to the carb or the timming it had no power and ran like crap, it turned out that the timming chain had never been changed and was stretched out, the guides were broken and the tensioner was worn down. After a new timming chain it ran great, so thats something you might check.

 

I had a problem similar on my old 81 truck. It ended up being a head gasket that would seal back up when the block to head gap narrowed after being warmed up and filled in the difference. But once cold again it would run like crap until it warmed up again. Problem went away when I changed the head gasket. I spent money on a new carb, vacuum lines ect. Even broke down and payed Toyota to look at it and they were stumped. Last chance was to change the head gasket and that worked. After looking back It would have been better to replace the head and check the decking on the block. Oh well I don't own that truck anymore.Good luck.