Q: Why does my truck misfire in third gear 1999 Ford F-150

asked by on February 08, 2017

Cleaned the maf sensor. Installed new coil bank. New throttle position sensor. Changed fuel filter. Changed air filter.New spark plugs. Still it misfired in 3rd gear when accelerating. Could the problem be the fuel pump. Low pressure output? Please help any other ideas?

My car has 238000 miles.
My car has a manual transmission.

Hello If you are getting a random misfire code at higher speeds then you may have a fuel system issue or an air flow problem. I would usually test the fuel pressure to make sure that the pump is fine and then test the air flow meter to make sure that it is putting out the right signal. I would then also check the exhaust to see if the catalytic converter is restricted as that would also cause this to occur. If you are going to have this repaired, consider YourMechanic, as a certified mechanic can come to you to [diagnose why the engine is misfiring] https://www.yourmechanic.com/services/engine-is-misfiring-inspection

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