Thread: IR heat sensor reveals one cylinder is lean

Ok so my girlfriends step dad let me use his shop and tools to replace my alternator, and he got a little dirty himself, helping out and what not...

After we got the new alternator on we were letting my battery charge in his garage with the car running and he showed me his IR temp sensor gun. It shoots out a laser and tells you the temp of whatever the laser touches...

Well the exhaust gas on header pipe on the 2nd cylinder from the left was about 400 degrees, while the other cylinders were all at about 250.

This was when the car had only been running for 2-5 minutes.

He suggested a larger spark plug because it was running lean, but to me, that's a bandaid fix. Something has to be wrong and I should be able to fix this with the correct size plugs installed...

so, partially blocked injector or fouled plug are my first two thoughts... anyone else have other ideas?

Definately sounds like a clogged injector to me. That might just get worse with time too.

Take the spark plugs out and post pics, thatll tell more..

^x2

doncha think it was retarded to go and say to just slap in a bigger spark plug though?? this guy has this FABULOUS 1964 Plymouth Fury with 340 and 4 speed auto trans that rebuilt himself.. I was pretty amazed at his suggestion for a fix..

I will yank the plug tomorrow sometime I suppose... and another one from a good cylinder to compare.

just wrap duct tape around that one part of the header, that'll do the trick

yeah, post some pics or just check the plug and injector.

my motor is spittin and sputtering, i need to buy a ve or swap in my old motor for now. too darn cold though.

Does the Fury have injectors? Or is it carburetted?

carburetted, he won't even upgrade to headers, it's all stock... just like off the showroom floor..

I said I thought if it were lean that it might be the injectors and he didn't think it was possible... weird...

Tuning Carbs != Tuning FI cars. Probably why he suggested it.

Maybe he suggested the sparkplugs cause he isn't used to injectors being a potential problem?