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DOBERDEWD 07-06-2010 03:21 PM

??? DIAGNOSTIC PROCEDURES FOR PO303 Misfire code ...
Greetings once again ...
I'm once again working on a friends 2001 F150 2x4 4.2 v6 automatic .....
He took it up north this past weekend and came back with a P0303 misfire code ... cyl #3.
I have eliminated the plug and the wire .... There is no spark coming from the coil for the #3 tower ...
I don't want to condemn the coil just yet as I know the coil has to be getting its signal from somewhere ....
I'd like to know which path I should take from here and the proper procedures to do so..... My Ford tech buddy is away on vaca and cannot be reached for comment ..... (how convenient is that ... the bastard ... lol) ...
Any help would be greatly appreciated ....
Thanks ,
The Doberdewd ...

Worf 07-07-2010 09:00 AM

A code P0303 may mean that one or more of the following has happened:

Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

Possible Solutions

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

DOBERDEWD 07-08-2010 10:40 AM

Thanks for all the insight to my issues at hand ..... I have found the reason that there was no spark coming from the #3 tower on the coil was that the coil was cracked on the bottom side where it is molded in .... When it gets real humid out or it rains , she starts missin .... So I replaced the coil pack and all is once again wonderful in Wausau ..... Runnin on all 6 .... :D
Thanks for the help .....
The Doberdewd

Worf 01-20-2011 08:14 AM

no problem thats what I am here for

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