Ford Repair: Stumble, mileage vehicles, high mileage

Question
95 tbird stumbleing off line but once the rpms are above 1500-200 runs like a raped ape an when the car is running at high speed it will stumble unless you get it to kick down an get the rpms up any idea i know not alot info but maybe just a thought on your years of work thanks

Answer
If this is the 4.6L engine, you more than likely need plug wires. Ford updated them several times in the nineties, and the latest Motorcraft wires have held up pretty good.
On high mileage vehicles, the spark will burn thru the boots on the spark plug ends, causing a misfire usually  under light load. At higher speeds or rpms this problem seems to be less evident once cruising. How old are the sparkplugs also? Might be time to do it all. If your wires have the cylinder numbers on them, then they are original and you have been lucky!

Pull a couple of wires off at the spark plugs, look for a spot on the boot, usually white, where the spark leaks.