I have a 1990 chevy k5, ive had a hell of a time with it. Its running like its out of time. So i timed it and their was no change. It is hard to start i have to spray carb cleaner into the intake for it to start. When its cold And it will idle in park and neutral but if u put it in drive or reverse it stalls. I cant get it to go faster than 40mph and it wants to choke its self out it seems when i give it gas. it will rev up but when u stomp it down it misses and sputters like it getting too much back pressure or like i said choking its self out. Ive replace the cap, rotor, coil the module under the cap and the vacuum hose from the pcv valve with no change.

Side note transmission (700 r4) is going bad so the speed of the rig may not necessarily be part of the problem
Any help would be appreciated.

 

have you tried removing the oxygen sensor from the exhaust? if the cat is clogged then there is nowhere for the exhaust gases to go and it chokes itself. and its an easy test remove the oxygen sensors from the pipe and see what happens