What causes a car to skip, hesitate, doesnt' do it all the time, getting worse,
Year : 2000Make : MercuryModel: Grand MarquisEngine: don't know
I have tried putting a solution in the gas tank for fuel injection cleaner. I have someone who said it was the spark plugs possibly the fuel filter. I recently lost my husband and knew all about cars. I know nothing and am at the mercy of the these shops that want to charge me a fortune. Sometimes it drives well and only has a little skipping, and then you can get back in the car it you start off and at about 40 -50 MPH it starts the skipping or whater. Today at one time it was much worse, I came home as I was afraid it would quit on me. I was told by a mechanic that it was the plugs. He drove it for a good ways, and it didn't do it hardly at all for him, and then today it was bad.
HelloCustomerand thanks for your question.
The most common cause for hesitation/skipping/engine misfire is the ignition coils. This vehicle has 8 of them, one for each cylinder. The problem is determining which one is at fault. If the engine light ever came on then the codes could be read from the computer with a scan tool to determine which one is at fault. If there is no check engine light then about the only way is with a Ford IDS scan tool which can access part of the computer to check misfire history and can also monitor the power balance of the engine in real time so that when it misses (or skips) the correct cylinder can be identified.This scanner can also stress test the coils individually and find bad ones even if the engine is not misfiring at the time of the testing.
Is there anything else that cause this type of problem? I noticed several months ago that somethingn was wrong, but it did it very little and sometimes it didn't do it for weeks, but recently it has gotten much worse. The engine light has not come on. Now it did several months ago only once.
There are numerous things that can cause the engine to skip. The coils are by far the most common. It could be a spark plug,especially if they are original. I replace probably 25 coils for every spark plug for engine misfire. Without being able to perform testing or actually evaluate the vehicle in person all I can share with you is what I have seen in my experience with this vehicle.
Mercury Senior Master Technician