91 GMC Jimmy s15 Pedal vibration and sound?

[anonymous1]

I have a 1991 GMC Jimmy S15, automatic, 125,000 thousand miles. Ran perfectly until earlier this week, started accelerating past 35 and it started to shudder as if it weren't getting gas. Nothing visibly wrong and the sputtering problem has disappeared as quickly as it came, but it left behind a few other issues. Vibration can now be felt in the gas pedal and it has become more resistant to touch. It idles normal and still drives, but it is missing some power and sounds slightly more rough as well. Already replaced the PCV valve two weeks ago, have been adding techron for the past three weeks, already checked the butterfly valves in the carburetor and they're perfectly clean, Distributor I believe to be fine, Distributor cap hasn't moved, Air filter is brand new, fuel filter is new, fuel pump is new, fuel sock is new, gas tank was clean installing the fuel pump, Air hoses have some very very minor cracks but nothing serious, all of this done before the problem stated. Bought all new spark plugs today and intend to install them tomorrow, along with new plug wiring. Posted this question late last night but am hoping to catch more people at this hour. Any suggestions or ideas could be helpful, and would be appreciated.
The PCV valve was two weeks before this happened, so I wouldn't think so from such a simple part. As for fuel additive, the Techron actually seemed to do the job pretty well. It made a huge difference in performance shortly after using it. Thanks for the answers so far fellas

 

[musicalgreasemonkey]

Could be the plugs. Or maybe a defective PCV valve. Did it start after changing the PCV?

Try Marvel Mystery Oil as a fuel cleaner. Its the only stuff i know that actually works well.

 

[lurch]

Try the plugs and wires and rotor button and dist. cap

 

[Lost on planet earth]

wow thats sucks.. well Check plug wires...See if at night you can see sparks coming from them..Pull the plugs and make sure they look nice and white on the inside end of them..if black change it...See if the engine moves back and forth easy when you have a friend step on the gas on and off... that checks for bad engine mounts, look for lose air hoses or cracks where they connect....Some have sensers on the airflow filter and they can go bad causing it to sound out of tune..mmm gosh..i know if you feel vibration on the brake pedal its bad rotors. It may need a complete tune up..plugs, plug wires, air filter, Distributor and rotor, PCV value..Put some good gas cleaner in the fuel tank, and last of all...Use carberator cleaner to spray all around the inside of the caberator..That should solve most of it.. then after that still having problems take it to a garage.....good luck