172 cup misfire replaced common parts

[Tj172]

My 172 cup started misfiring yesterday on cylinder 2, ive replaced the injector, plug, lead and coil with known working parts off my other 172. ill run a compression test tomorrow, but is there anything else i should be checking? Rs tuner brings up a generic misfire code but nothing else.

 

[Barnett182]

Map sensor?


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[Tj172]

Unplugged it and it died but i haven't swapped it out yet, could it cause a cylinder specific misifre?

 

[Barnett182]

I would imagine so! My did the same thing thought it was a lambda so stripped the underside of the car as the thread stripped on the manifold, only to find it was this! Try spraying break cleaner in it and see if that helps first


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[Tj172]

Ok mate ill just swap it with my other one first and ill check lambda too. Thanks

 

[Barnett182]

Also you could try swapping the leads like swap the cylinder 2 for cylinder 4 and see if the code changes to cylinder 4 then you would know where the issue is


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[Trophyboy2017]

Compression test would rule out a few things so id try that first bud.
This was exactly how mine started and found out piston & rings had melted. Check my piston detonation thread above.

Any smoke coming through oil cap?

 

[masekwm]

Doing the right cylinder?