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Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 23821
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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1999 ford expedition 5.4 po340 code. Runs fine at idle. Runs

Customer Question

1999 ford expedition 5.4 po340 code. Runs fine at idle. Runs terrible from 1500 thru 2200 rpm. New pcm new alternator. Replaced cam sensor. No difference. Brought it to ford they ckecked for wire issues non found. They called and said runs fine they didn't fix anything. Just started running fine. Picked it up made it home runs like crap again
Submitted: 1 year ago.
Category: Ford
Expert:  Wayne Crawford replied 1 year ago.

Hello. My name is ***** ***** I will be helping you today.

Try unplugging the voltage regulator plug on the alternator and see if it runs better.