W124 Misfire on one of four cylinders

[2phones]

Hello,

I'm wondering if anyone has any suggestions for fixing a misfire I'm experiencing on one of the four cylinders in my 1991 230CE.

Checked all the plugs and they are all providing a spark.

Thought it was a clogged fuel injector as my car was sitting for a few months. Replaced the injector on that cylinder but nothing changed.

Did a compression test and all seems fine there.

Any advice would be greatly appreciated.

Thanks
Stephen

 

[Peter C1974]

Have you checked the HT leads and distributor cap?

 

[LostKiwi]

If you have one of those infrared laser thermometers aim it at the exhaust ports and one will be colder than the rest if it's a cylinder specific ignition or injector fault. May help diagnosis.

 

[Peter C1974]

If you have one of those infrared laser thermometers

Yeah, who doesn't!

 

[LostKiwi]

Yeah, who doesn't!

They're only £20 or so from Maplins and very handy!

 

[DREAMER NO2]

Open the bonnet when its dark , look for arching my friend said his was shorting out inside the spark plug hole .From the side of the metal plug holder and the head. I have the little pen type tool to pop on the plug wires ,you can see if its firing or not cost £6 ebay.

 

[jibcl500]

Replace the plugs dizzy cap, rotor arm and HT leads then report back.

jib