[Bluejay]

[quote=bsteele;3240173]

Originally Posted by bluejay432000

Extraction is usually successful if the TSB is followed closely. That means using the correct solvent and letting it soak the correct time, etc. Those that have broken plugs can usually extract them with the special tools. It should be rare that anyone has to remove a head. Also, I think it is important that gas with a good detergent is used. I have also seen some posting that they broke a plug after running p1 octane. Little did they realize they were doing more harm than good when the engine was tuned for 87.

BlueJay432000,

Are you saying that it cause's more harm to the engine-plugs to run premium unleaded fuel in the KR Truck? I should stick to 87 as opposed to 89 or 91 fuel ? Please educate me, thanks.

The systems are tuned to run on a specific octane. Our engines come from the factory tuned for 87. If you run a higher octane, it causes a delay in the firing of the cylinder, which can add carbon deposits to the cylinder. Higher octane creates more power by delaying the explosion, but the engine must be tuned for it so that the timing of the explosion is correct. So, some people, thinking that the higher octane must be better, run it on an 87 tune, and they may be actually adding carbon buildup on the plug stems. I have seen where guys had a problem with plug removal and said they had "even run 91 octane". So, in essence, what they did was pay more at the pump to worsen the plug problem. Now, if you have a tune in the truck computer that adjusts the timing to take advantage of the higher octane, whole different story. It will run just as clean and produce more power doing it.

Hope this helps.

An additional thought. I bought a new Expedition back in late 1999, a 2000 model. when I picked it up, the dealer warned me that it was tuned for 87 and to never run anything else as I could actually do more harm than good.