Mechanics

MYSTERY ENGINE MISS

1998 Ford F-150 • 170,000 miles

I have a 98 f150 2 wheel drive standard with a 4.6 the engine has a miss and when I put it on the scanner it comes up with a miss on cyl#4 I have replaced the fuel injector the plug the wires and the coils on the engine but it still has a miss. I have checked for vacuum leaks and found none. I am at a lose as to what else it could be. Can you help me please?
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Martinrobertcairns
September 14, 2012.



Check its compression to see if it varies with other cylinders.

KHLow2008
Sep 14, 2012.
I did a compression test and cyl #2, 3, 4 were 165 and the rest were 155.

Tiny
Martinrobertcairns
Sep 15, 2012.
Compression results seems ok.

Have you checked the EGR functions and operations?

KHLow2008
Sep 15, 2012.