Fuel

[98StangGT]

So I filled my car up with premium gas 93, and its idles alot better, but still notice lil bit in throttle response, could be fule filter? or fuel pump?

Trey

[Thomas91169]

a little bit of what? hesitation?

run some seafoam through the motor, then change out plugs and filters(oil, fuel, air).

automatic? could be tranny hesitation(4r70w normal sucky behavior)

[98StangGT]

Its a Standard and yes hesitation when its throttled, I did put seafoam in the engine a couple weeks ago, but did not change out plugs, and filters

[Thomas91169]

hrm, definately change out the plugs after a seafoam. 98's have plug wires correct(as 99+ get Coil on Plug), so id check those as well.

ive always found stumble/hesitation to be caused by igntion/timing, rather than a fuel problem.

[SpectorV]

fuel filter, plugs, plug wires, inspect coil packs. That might make all the difference. Start small and work your way to the harder more expensive items but DEFINATLY change the fuel filter EVERY year.

[bosscityboy86]

I would go with changin the fuel filter, spark plugs. I know in my 2000 ford F-150 4.2l v6 i change my fuel filter every 15000 miles and it has 142000miles with a lot of upgrades and no problems.