Q: My engine is misfiring.

asked by on January 11, 2017

replaced, plugs acdelco regular copper oem gapped at 45, wires acdelo, cap and rotor accel brand, coil duralast, fuel pump sprecter premium with sending unit. misfire under acceleration and really noticeable when in gear low rpm. was doing this before I changed anything.

My car has 65000 or 165000 according to odo miles. engine is 305 My car has a manual transmission.

Hi there. Check the injectors on the throttle body and see if they have a metered spray. If the injectors are spraying correctly, then there is a vacuum leak on the engine and is only effective when under a load and at low rpm’s. Check all vacuum lines and the brake booster. Replace any cracked, broken, or missing vacuum lines. If all of the vacuum lines are good, then there could be an internal issue with the engine, possible burned valve or rings. If you need further assistance with your engine having a misfire, then seek out a professional, such as one from Your Mechanic, to help you.

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