When traveling up a grade in 4th gear at 50mph, my engine misses. If I mash the gas it just gets worse. I've replace the fuel filter, plugs, air filter, added octane booster to super unleaded fuel, and still no change. It won't do it on the flat unless I stick it in 5th and really get on it. I was thinking wires next?
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91 XLT 4X4
4.0L 130K
5spd
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91 XLT 4X4
4.0L 130K
5spd
