Q: Rough idle random misfire and hesitation when accelerating

asked by on November 03, 2017

Rough idle, random misfire, and hesitation when accelerating; new plugs and wiring, just did oil change,cleaned throttle body, and Mass air flow sensor. I gave fuel treatment and engine restorer, which there is definitely improvement but still having issue; any suggestions????

My car has 151000 miles.
My car has an automatic transmission.

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Hi Brandon. Thanks for contacting us tonight. If you were having these same symptoms prior to the services you completed, then I would assume that either you’ve got a misfiring or clogged fuel injector or a distributor (ignition coil) that is worn. If these symptoms have popped up after the service, I would double check your spark plug wire connections (making sure they are attached to the correct plug) or check for a vacuum leak. A loose electrical connection to the crankshaft position sensor can also be a cause of these type of symptoms - as could ECU issues. In worse case situations, damaged valve springs and other cylinder head components. You might want to have a professional mechanic help you diagnose this issue.

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