VW Polo 1.6 misfire

[bobbin1982]

Sorry not sure if this is allowed here but if not please delete

The problem is my 1.6 polo on a 1998 misfires on cylinder 4 while idling but not while driving (odd i know)
I have replaced the dizzy cap twice, Plugs ,leads , Coil ,rotor arm

The only thing i can think of next is maybe the crank sensor?
Has anyone got any ideas before i stack it into a tree to make an insurance claim


Andrew

[Speedtouch]

I would do a compression test, to ensure you're seeing even compression readings across all four cylinders.

[bobbin1982]

sorry forgot to mention i did a compression test and it was good
14/14/13/14

So nearly perfect

[teamalsoran]

could be an air leak, try spraying around the inlet manifold gasket with wd40 or similar whilst its running, if you have an air leak it will pick up the "dead" cylinder when the wd gets sucked in. faulty injector is anotehr possibility