[TCGrove]

I've got a 99 Blazer 4wd with the 4.3L. I've had every problem known to man including yours. I did all of the following: New plugs, wires, distributor, fuel filter, cleaned the MAF sensor...but honestly I think changing the O2 sensors did more for this problem. I makes sense given the sensors have some warm up time. I eventually gutted the cat converter but it started throwing a code. So I got the little extender that pulls the sensor behind the converter out of the gas stream. It runs great and no more hesitation. I swear I thought I was going to get rear ended sometimes pulling out in traffic. Eventually I also replaced the entire distributor while fixing the intake manifold gasket at 155,000 miles. The little gear on the end was shot. The fuel pump totally went out when it bit it. I hope this helps. Look at the O2 sensors.......