p0305 on 1994 mustang

Hi everyone,

New to this forum and I have a 1994 Mustang that is driving me nuts. It keeps putting up the cylinder 5 misfire code,P0305, and I have changed plugs, plug wires,coil pack,injector,throttle position sensor,crankshaft position sensor, and cleaned the MAF sensor, all with no help. The car acts like it is running on 5 instead of 6 cylinders. I noticed the idle is down around 500 rpm where it was about 800-900 rpm before. The kicker is that when I'm driving the car it will smooth out and run fine for a few miles then drop back to missing again. Also acceleration is difficult from a stop.

Any helpful suggestions will be greatly appreciated!

Del

compression or cylinder leakage test!

thanks for the reply, Jeff! Forgot to mention that I had done a compression check and all cylinders came out around 150

Thanks,
Del

Well unless it's a command problem on the injector or ignition to that cylinder then I'd still be inspectting the valves on that cylinder then! What size engine?

the engine is the 3.8l v6. Sounds like it's time to break out the hand cleaner and take the head off that side. Can you give me an idea of what I might see if I have a valve problem?

Thanks,
Del

Some guys flip the head over and fill the combustion chamber with mineral spirits to see if there is any leakage. If no leakage then remove the valves and check there faces and seats but before ripping the head off I'd verify everything electrical is present at that cylinder, good spark and injector pulse! Might be worth having a pro or the dealer check it out! Those 3.8's were used in all kinds of Fords so they should be quite competent with them