'89 Olds Delta 88 - why does the spark plug in cylinder #5 do this?
 

I have a 89 Olds Delta 88 Royale Brougham with the 3800 V6. In cylinder #5 is causing the spark plug to ash up and I can't figure out why. It is only cylinder #5. I bought a new set of Berg Warner wires and a new coil pack and replaced the at the same time hoping it would fix my problem but it didn't. The Coil pack was the original with the car and it was failing all the test so that is why I replaced it. Also cylinder #5 has a new spark plug in it at this moment. I bought a few extra due to this problem. All of the remaining spark plugs have been in there a little over a year now and they are doing great. They still look brand new. I will be adding a few pics of the plug below so yall can have a better look at what I am talking about. Also my book says the ash looking stuff on the spark plug means it is not burning all the fuel in the combustion chamber. So any and all help will be greatfull. Thanks.

I don't recall, but that's either a lean burn or rich burn condition. I forgot, was that a fuel injected motor?

Yes it is fuel injected motor.

That looks more or less normal to me. This is ash fowled.
http://www.verrill.com/moto/sellingg..._ashfouled.jpg A build-up of combustion deposits stemming primarily from the burning of oil and/or fuel additives during normal combustion ... normally non-conductive. When heavier deposits are allowed to accumulate over a longer mileage period, they can "mask" the spark, resulting in a plug misfire condition.


This is normal.
http://www.verrill.com/moto/sellingg...lug_normal.jpg Combustion deposits are slight and not heavy enough to cause any detrimental effect on engine performance. Note the brown to greyish tan color, and minimal amount of electrode erosion which clearly indicates the plug is in the correct heat range and has been operating in a "healthy" engine.

depends, if they all look like that over a period of time then its fine but if just that one turns brown in a short time its likely the injector gunking up and running lean

It happens on that one spark plug about every 500 to 600 miles. I have been keeping track of the miles on this issue so I could say how long it take to cause this.

you could move trade that injector with another to be sure but i think your going to have to replace that injector.

Well I run SeaFoam threw the gas at the beginning of every month. Would that help the fuel injector any or not.

It helps, however, using seafoam to much will degrade your O rings.

I asked the same question and they said it wouldn't hurt anything but it seams that it just may due something. But why would it only affect a single fuel injector not all the remaining injectors.