I have a 1995 Mercury Cougar XR-7, with a 4.6 Liter V-8, that has 157,000 miles on it. It has been regularly maintained. It is running awful and showing codes for Cylinder #1 misfire and Cylinder #5 misfire.

It has been to 2 Ford dealerships and been examined by 2 other experienced certified mechanics. It has left several people pulling at their hair, trying to figure it out.

1 Ford dealership mechanic couldn’t find an exact problem and suggested I replace the engine – I’m not ready to accept that answer.

The other Ford dealership mechanic said that it had a bad intake valve, so I had a scope ran in the cylinder and found no bad valves.

1 Certified mechanic said he ran every test he possibly could and could find nothing wrong with it and said that theoretically, the engine is in perfect order and should have no problem, that he could find and that he couldn’t help.

The other certified mechanic ran all the probes and even used a Sun machine on all the electrical leads and it came back in normal parameters and that he couldn’t determine the cause of the problem.

Here is a list of things that have been done to rule out problems:

Can a computer be causing the problem? Any ideas of where to go or what to do next? Any insight would be sincerely appreciated.