new user needin some tech advice

[Grif89D21]

I have a 1989 D21 with the Z24 motor, I've owned this truck since it had less than 3 miles on it, it has somewhere in the neighborhood of 350K now "the odometer gave out about 7 or 8 years ago at 259K. Been a great truck I've put it through the ringer and haven't had to do too much to it but lately it stalls when I accelerate I am wondering if someone here can point me to a Service Manual, I suspect the TPS , and would like to check the voltages to ensure that they are within specs. I have changed "1 at a time" all of the vacuum lines, both coils seem to be firing, although it will only start with one of them disconnected if I swap the coil wires to the other coil it won't start but it shoots a nice long spark when it is running before being swapped,air and fuel filters have been changed, and the catalytic convertor does not glow in the night after being driven. Any and all assistance will be greatly appreciated, I know I'm not the first to have this problem

[Rev_D21]

Welcome to NICO. Great to hear an oldie is still on the road. A word of advice though, you don't need to create 3 different threads in different forums to get a question answered. I answered this in the truck forum for you already. Once is enough, give us a chance to research and respond. It makes for a cleaner forum. Now check the truck forum because I replied to your issue in there.