Okay so back in April I bought a 1990 Mazda B2200 that has a carburetor and it ran fine for about 2 days then died. We pushed it up a hill and then ran it down the hill and it fired up but had no power to in, then once it got to the bottom it died and would not start again. Since it was my first Manuel Transmission we figured all the jumping around caused the timing to jump. So we reset the timing and it still wouldn't run. While in pieces we also replaced the timing belt and other belts. After some further examination we realized that the lower pulley was loose so we took off the timing cover reset the timing again after tightening the pulley. We also replaced the distributer cap and rotor for good measure, but it still will not start. It has spark, compression, and fuel is running fine. I tried fidgeting with the idle speed control but to no avail. I can however put it in first gear and turn the key and it will put-put up the driveway. To me it seems like it has everything needed to start but it won't. Any thoughts?

Thanks,
Caleb

 

Just how much compression does the engine have? Has the compression been verified with a known to be good tester, if so, what are the numbers?
You'll need to find out what the minimum allowable compression for the engine is, and compare it to the actual compression. Once you know for certain that the compression is @ or above specifications, you can move on to other possible causes for it not running.

 

OK, lets assume the timing belt/cam timing is correct, for the moment. You need to first determine if the issue is spark or fuel. Spray in some aerosol starting fluid, mash the pedal down, try to start (do this a few times). If it runs for a few seconds, even roughly, then you have a fuel delivery problem. If it doesn't run at all doing this, likely spark; pull a plug wire, insert a bolt, hold that 1/4 inch from engine metal, have someone crank it. If the engine doesn't spin fast enough, that can also make it tough to start.

OK, what historically goes bad on these trucks as they age? Electrical part of ignition switch, rust in fuel tank that clogs the fuel filter, clutch hydraulic systems (not an issue in your case).