Hi, I'm new here and just hoping to gather some answers. I have a 1998 mazda b2500 2wd, and I can't get it to run unless I have the entire intake tapped off untill it only breathes through a hole the size of a standard sharpie, even then it won't run sometimes, and it when it happens to run it won't accept any throttle input over 1/4 and will only rev to 2500 then acts like it's cutting fuel or spark, and at full throttle it'll rev to 2500 the act like it's on a limiter then dies when I let off, I have changed all 8 plugs and wires, fuel, fuel filter and the oil. I'm at a total loss here and don't know what to do.
Have also changed the throttle body gasket, intake manifold gasket, and IAC valve

 

Welcome to the forum

Not alot to go on
Could be clogged exhaust
Pull off/out the upstream O2 sensor so exhaust can get out and see if it starts OK

If you have a vacuum gauge you can test for clogged exhaust with that
Should have 2" of vacuum cranking
After startup it should jump up above 16" or more, if low or no vacuum running then clogged exhaust for sure

New air, with fuel, can come in if the "old" air can't get out, its liking trying to run a pump with a blocked output, it just can't pump

 

Well I can tell ya clogged exhaust definitely isn't the issue, the catalytic converter was cut out of the truck before I got it, it ramd just fine when I got it, it's been hit or miss since I put a clutch in it and did the work I did to it