Engine hesitates during hard acceleration on 1993 GMC Vandura 2500

170K miles on original engine. Occasionally takes a little longer to start recently and will not accelerate crisply when pushing on gas pedal, sort of falls on its face, no power, like no fuel or timing not advancing? Could it just be dirty fuel filter, bad fuel pump, or issue with ignition timing?

Asked by for the 1993 GMC Vandura 2500
Sounds like it needs new spark plugs and cap and rotor, possibly the fuel filter could need replacement also
1 more answer
I have a 95 gmc vandura which i a currently experiancing similar problems, engine wont start all the time, when it does seems like theres not much wrong until you get moving, then power goes in and out in pedal, i have been told by multiple mechanics that its the spark plugs or fuel filter,vaccum leak(bad hoses around carb) also the MAPS sensor. I have replaced all of those and decided before i went completely broke to get a diagnoses done so i can stop shooting in the dark, i personlaly believe i have a bad fuel pump but mechanic seems to think that there is a bad sensor somewere in the van. Im waiting to hear back from him, if he is wrong then i will be replacing a fuel pump. Hopefully my pain will help pevent some of yours. Good luck!