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.

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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