I have a 1997 gimming 4.3

No vac leaks...have you put a vacuum gauge on a manifold tap and checked the vacuum reading? Vacuum should be steady at 17-22 inches. If much lower than that, below 15 inches, you may still have an air leak-check the intake manifold gasket, and throttle body assembly gasket. Spray carb cleaner around the sealing areas while engine running, listen for rpm surge or change in pitch. Does the big air boot have any tears or punctures, and is it clamped down tight?

What is the fuel pressure reading? Does it match specs for your vehicle?
A cylinder compression test may be called for if you cannot find any other reason for the misfires. Look for low compression figures that may signal a valve problem, or valve timing problem.

What fault codes did you receive on the engine computer scan test.

sounds loke timing off and or crossed wire or bad wiring check connections to plugs may have a bad wire or connection

Did you change TPS sensor[RPM].

I'm assuming you replaced the fuel filter when you did the pump.
You'll have to try to figure out if you are loosing fuel to the injectors or spark to the plugs to proceed.
Its possible something is failing inside the distributor among other things.
I'm also assuming you have checked the computer for trouble codes.

I think you're on the right track, have you replaced fuel filter recently? That and check for vac leaks at engine (vac hoses & intake hose - bellows)

TPS probably not cause surging idle. Could be IAC motor, could be MAF sensor. If you dont have a check engine light I would be thinking IAC motor.

run engine codes, had same issue once before it was bad computer good luck

i would first check the timing and if that does not fit i would take the cover back off and look at the belt for a bad or missing tooth

firstly remove the inlet fuel line at the filter and and blow down line with a compressor ,removing fuel cap first,if this doesnt work then it could be fuel pump pressure of air flow meter ,but iam often wrong with this sort of thing and it turns out to be the radio,all joking aside try blowing out fuelline doesnt work??then take it to dealer for computer check