Over the past week or so at a stop or when in park when I depress the accelerator the truck bucks and runs like hell for a few seconds and then goes away. I have not changed the fuel filter in a at least three years and it still has the original fuel pump. Should I change the filter and then try to check the fuel pressure? Are these signs of a fuel pump going bad?

 

Could be a number of things. But since you can reproduce it, yes, checking the fuel pressure with a gauge would be a quick and easy place to start.

When was the last tune up with wires, plugs, cap, rotor, and general electrical connection cleanup?

 

Changed the plugs and wires in May 2018 along with engine bay cleaning.

 

Should the pressure hold at 50 psi? If it drops can that be pressure regulator on rail or bad injector o-rings.

 

On a 94 the pressure spec is somewhere in the 30's for PSI (on 97+ it's approx. 50psi). I'll see if I can dig up the exact spec for you.

 

Thanks.

 

87-95 = 31psi at idle with vacuum, 39psi without vacuum
96-01 = 49psi +/-5psi

 

It should hold 31psi - if you disconnect the vacuum line from the regulator it should jump up to 39.

 

Thanks. Will test and report back.

 

Checked the TPS last night with meter readings were erratic. Removed throttle body and replaced TPS voila bucking is gone back to normal. Thanks to all for opinions.