Fouled Plugs
 

I have an 83 maxima with the L24e engine. 165,000 original miles. Ran like a top until it started fouling the plugs on cyls 5 and 6. The plugs are gouled with carbon, not oil and are not wet - appears to be incomplete combustion.

The compression on all 6 cylinders is good and the engine does not burn any oil.

I would like to do a L28 conversion with this car, but need to get it running and driving again so I can smog and register it. First thigs first...

Any ideas as to what might be causing this?

Check plug wires, distributer cap, plugs etc. With clean plugs, does the idle change if you pull the plug wire on each cylinder?

Hey Darrel! Have we met - 2nd Creek or State Trooper track? Do you have a white late 70s z?

Anyway, Dist cap is brand new, brand new NGK silicone wires and new plugs (first all 6, then just the 2 that are fouling).

I have pulled the plug wires while it was running but cannot remember the result. I want to say that the idle DID NOT change. I am just now preparing to take the car out of storage and get it back up to denver so I can work on it.

Trying to get some ideas so I can attack it.

-ben

It could be a bad plug wire, bad spark plug or bad cap. Check for arching inside the cap. Then check the the idle change by pulling off each plug wire. When was the last time the valves were adjusted?


I left a big hint on what car i drove in the 2nd creek thread. ;-) If you have high speed and downloaded all the pics you will see which car I drive. ;-) The late 70's is a '79 280zx that belongs to Larry Brooks. I have been to the state patrol track once, but didn't track it. I was having fuel problems.

There is a guy with a green 914 that always comes out for the track days. His mom brings out her z31 T. I never was very good with names.

I can't remember if the installation of the NGK wires coincided with the problem it has been so long ago. I have another set of wires though, I will throw those on and see what happens.

My father and I adjusted the valves shortly before I stored the car, so they should be good.

Any chance it might be burnt valves or another mechanical issue? I can't imagine that it would be electrical / fuel metering issue.

-ben

Since it doesn't burn oil & has good compression, I'm gunna say that it's not bent (nor burnt) valves.

And since it's a flooding problem, I would imagine it has something to do w/ spark, or w/ the fuel system.

Does the engine crank over & run at all right now?

Thank you for your insight.

I can run and drive the car all day, but after a while of running cyls 5 and 6 will stop firing and it will lose a considerable amount of power. I typically just have to pull the plugs and clean them and it will come right back to life.

So either the sparkplugs aren't sparking on those 2 cylinders, or those 2 injectors are spraying too much (stuck open). Pull a spakplug wire one at a time & make sure they are all sparking.... Also, it might be a good idea to run some fuel injector treatment.

I will start with the ignition components and work my way to the fuel injectors. I do have spares if need be. Thanks.