Mechanics

I HAVE A 04 DOHC WITH COIL ON PLUG, SHOWING CODES P0351 P0352 P0353.

2004 Ford Taurus • 93,657 miles

The first 3 seconds after start up it runs smooth but once it idles down and its back to misfiring and misfires thru the entire rpm range. Cyl 1 has no change at all when the coil is unplugged. Tried new plugs. Switched coils from cylinders 1, 2 and 3 with 4, 5 and 6 still same problem same place. It runs like its on 5 cylinders and at times it acts like another cylinder is dropping out. I pulled each coil and visibly made sure there was spark although im not sure if its firing in time or not. Ive checked wires from all connectors back to the pcm and they all checked out fine. Ones shop said it just needed a pcm so I got one and it runs exactly the same so that was 300 bucks wasted. I bought this car cheap from a friend thinking it would be something simple like corrosion since he said it started doing it within mins of washing the engine at the car wash. I have found absolutly no corrosion anywhere. What else could it be?
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Zhyde9008
February 17, 2012.



Check for vacuum leaks and fuel pressure. Spray choke cleaner around head/intake area if rpm change it leaks. Check resistance in cols an dplug wires.

Hmac300
Feb 17, 2012.
Check all that and all is good. Could it possibly the maf. I know on some gms a bad maf can bring up a totally different code

Tiny
Zhyde9008
Feb 17, 2012.
You 'll have to check the crank and cam sensors, they may have saltwater in the harness, if it is put dielectric grease in it. This cold also be a bent pin at pcm or one of the coil drivers. Or a shorted wire that you would have to check to see if it is any good going back to the pcm. However a cranks sensor can have to much resistance and give a problem without setting a code so you shold check that as well. I dont' know what it's supposed to be though.

Hmac300
Feb 17, 2012.