I need advice as I have about had it. '88 Samurai, stock 1.3 with a Weber I installed 2 years ago. It has been running great. About a month ago while going slow in 1st gear it was loping along terribly. I thought it might be water in the gas, so I added Heet, and Seafoam. It seemed to get a little better and when I got down to 1/4 tank I filled with fresh gas from different station. Problem continued to get worse. Just to cover everything I replaced distributer cap, rotor, plugs, plug wires. Installed new fuel filter and pulled fuel line to carb. Cranked engine and fuel flow was strong. Replaced all the rubber fuel lines. There is no gas smell to the oil and level has not changed. Motor does not smoke. I used propane to test vacuum leaks and thought there might be a leak around the evap can, so I bypassed it and removed EGR valve and made a blank plate. I have been trying to determine if there is a vacuum leak around my Weber adapter but get no response that is consistent. I have replaced the adapter once and was a problem but the vacuum was very obvious. It went from running great to barely running. I feel the age of the Weber makes it less of the problem but I may be wrong of course. My brakes are good and the brake vacuum lines did not react to the propane test. I am wondering if I have a cracked manifold. I think the more I work on it; the worse it is running. Any help would be appreciated and sorry for the long rant.