IDing stuck injector

[Oliver]

Before backing off the pipes to each injector one by one, I was wondering if anyone had tried using an infrared thermometer to see which cylinder is noit firing. I am assuming that this should be done right after starting a cold engine so the heat of combustion doesn't heat up the entire block.

[rick s.]

you might get a better result by using the ir thermo on the exhaust manifold rather than the block.

[Oliver]

I think the water jacket might diffuse the temp and make it hard to be specific. Interestingly a lot of people have looked but no one has a suggestion. I guess SOP is just to remove them all and send out for pop off tests.
With modern fuel injection systems you can block one injector at a time. Guess I will bite the bullet and remove them all.

[gsholz]

To test, can't you just loosen the fuel line to the injector while running in idle? If there is no change in idle you found the bad injector (or bad cylinder).

[Oliver]

I am going to try that, thanks. FYI, Brian Smith told me to use mechanic's stethoscopes and listen to the fuel pipes where they enter the valve cover.

[Tom Overs]

Hope I'm not too late with this.....
Please be very careful as the fuel is delivered at very high pressure.
Tom.

[Oliver]

Thanks for the warning, Tom. No you are not too late. BTW, Brian gave me the same warning which is why he advised the stethascopes.+

[Richard Werner]

Using a flare nut wrench gives more control and you don't risk messing up the nut.