I have a 1985 S-10 with the carburetated 2.8l v6 with 127,000 miles. The problem I have is that the engine is missing and knocking when under load. It idles fairly well but as soon as you start driving it starts missing and lacks power especially as you get to higher speeds. It is topping out at about 35 mph and starts to miss, knock, and buck. Timing is perfect at 8 degrees, new fuel filter, new fuel pump, newer plugs, wires, distributor cap, rotor, head gaskets, and intake gaskets. All spark plugs are getting spark and look fine when pulled. It also has a newer CAT and has been sea foamed. All the plugs are gapped correctly, no water in distributor, no cuts on any wires, firing order correct, no fuel leaks, fuel pump is pumping fine. I am out of ideas and with so many things being done recently im not sure what else is left.
This doesnt realy help me too much because I dont have fuel injectors, oxygen sensors, throttle position sensor, IAC valve, MAF. It has a new mechanical fuel pump so it has good pressure, the EGR valve is newer, all vacumme hoses are newer and all the ignition parts are newer. So pretty much everything on here my vehicle is not equipped with or has been very recently replaced.