Mechanics

INTERMITTENT MISS (SCATTERED, NOT JUST 1 CYLINDER)

1986 Mercury Station Wagon • 125,000 miles

Have 2 canadian-built ford wagons ('86 and '89). Both have 302pfi engines. Both exhibit an intermittent miss at light load (particularly after the trans shifts) which is much more pronounced when warm. Have replaced just about everything in the ignition system, tried disconnecting the egr valve, cleaned the iac motor, all to no effect. Strange thing is, the problem will disappear for a day, a week, or a month and suddenly return with nothing having been done to the car. Absolutely stumped. Any thoughts? Thanks in advance.
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Larry p
July 20, 2012.




Symptoms indicates the problem most probably is related to the ignition spark system and more likely a loose connection somewhere rather than a bad component.

KHLow2008
Jul 21, 2012.


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