INJECTOR @ CYL #1

[i-Zer0]

I just completed a spark plug job on my G50. All went well and and as expected until I got the the last one. Spark plug #1! The electrodes were normal looking but the threads were completely covered in oil! As if the plug were dipped in oil. The electrodes were dry, however. This seems indicative that the plug was indeed firing, yet it was not burning any fuel. Meanwhile I have detected a miss in the engine running, at all RPM's, which is what initially prompted me to change the plugs in the first place. I need to know why I didn't get a check engine light as the injector seems to be clogged. Going on this, I also need to know if Mystery Oil should be tried first in place of replacing the injector entirely (??hopefully without removing the plenum?? {please say yes}. There is a wrecking yard in Mesa, AZ that has a '92 G50 w/ the injectors still on it. But I want to get a little feedback from the forum first. ***Thanks!***

[qship96]

leaking valve cover gasket,very common.search and you will find tons of info

[Raxephon]

To get you started:

zerothread?id=107690

zerothread?id=99793

And no, the plenum does NOT have to be off to remove injector # 1.

[Q451990]

The oil on the threads, and misfire are not related. The oil is from leaking rocker covers. The miss could be any of your injectors. I would ohm test the injectors first. If that doesn't indicate a problem, you'll need a power balance test or an IR thermometer to look at the temperature difference between cylinders (compare temps. on each leg of exhaust manifold).

When I had injector failures - the plug on the bad cylinder was pitch black. Did any of your plugs look that way?

Your only hope as far as a flush, is a pressurized flush. This is a procedure where the fuel lines are looped back to the tank, while the car is run on a canister of pressurized cleaner.

Heath

[qsiguy]

As far as the '92 injectors, if they are original I wouldn't buy them or you're just replacing something bad with something that may already be bad or is really close to going bad.

Unrelated but I need a power window regulator and found one on ebay from a '94 (which I have) but opted not to get it as it's just as old as the one that just failed in my car.

Some parts should just be replaced with new some are ok to use used stuff. If it's something that can and will wear out I'd look for new or only slightly used.

My $.02