What COMMON reason is there for rough Idle and hesitation on acceleration from a stop with a 3.8 Cougar 1991 year?

Answer 1

Coud be a few things actually. You may need a tune up. Start by going to AUTOZONE, and have them run a free OBD Check (on board diagnostics check). Basically, you are having them see if any trouble codes were recorded by the cars computer. Otherwise, start with checking the plugs, and make sure they are in good order (clean, properly gapped). If you plugs are bad, or you are unsure how old they are, its worth the while to get new ones. It would also be a good idea to replace the plug wires as well. When you do replace them, make sure to secure them tightly to the plug. You should feel them "pop" on. Will Titus Ford (formerly Fordparts.com) will have the factory stuff at an awesome price. DO NOT GOTO YOUR LOCAL DEALER. DO NOT BUY FORD RACING PLUG WIRES. OEM's are actually BETTER. Don't get the economy ones either! Its also a good idea to then replace the air filter, and fuel filter. While your at it, make sure the air manifold is clear of build up. I also recommend switching to Synthetic oil, and running some STP Fuel Injector Cleaner on your next fill up. Do so for a couple fill ups actually. If you haven't done so in a while, have your coolant flushed by a local shop, and replace the thermostat while they are at it. This will help to make sure your engine stays cool in the summer, and warm in the winter. Keep the engine clean with a wash as well. Spray on some SIMPLE GREEN ALL PURPOSE DEGREASER/CLEANER, and gently/lightly spay or mist the engine off with your garden hose and a nozzle. This too will also help it to run cooler, and increase your MPG's! GOOD LUCK CODEBLU