engine mis fires when shifting into overdrive on 2003 Ford Escape

2003 ford escape,, 80.000 miles. easy miles, well taken care of,driver side back axle seal, diff entrey, leaks, others i know same issue same side.also the mis just started this winter.i would spray wd40 on electric connections and use lucas gas treatment in gas for water in tank and issue stopped, it has started again to misfire again, only when it wants to shift into overdrive,, or when i go up inclines,the mis fire issue started this summer also when i cleaned motor off with simple green and low pressure garden hose, i air blowed all connections and wd40, after i started and motor was missing. again ran great after oil spray..now nothing helps issue.please advise next step

by in Plainwell, MI on March 23, 2014
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1 answer 2 comments
ANSWER by , March 23, 2014
Probably ignition coils, with information stated. When the overdrive, or lock up happens is when you will notice most anything the engine is doing.
COMMENT by , March 23, 2014
is ther any way I can test coils myself and with what and how,, like to fix myself, before i take it to dealership and --ya know what they do $$$$$$$$$$$$$
COMMENT by , March 23, 2014
They are well known to break down; You can scan for misfire codes, which are not normally there in many cases, to find which are breaking down. Sometimes I take it out with one of my better scan tools and monitor misfire data to find out which ones are breaking down and sometimes replace those only, and sometimes I replace all of them, depending on the customer request. Does it misfire a idle any, if so you can disconnect the connector at each one at a time to verify, if only under a load it will be hard to find without a scanner to read misfire data. You could replace one at a time and switch positions after driving and see which one has stopped misfiring when you hit the right position or replace them all.