Fixing carbon deposits on spark plugs on 90' Geo Prism

Tiny
RUDYSEW
  • MEMBER
  • 1990 GEO PRIZM
Geo Prism, 1990, 171,000miles 1.6 engine. New plugs and wires are good, but keep getting carbon deposits on all 4 plugs. How do I fix to not get these deposits on the plugs? Thank you.
Rudy S.
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Thursday, August 2nd, 2007 AT 12:19 AM

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Tiny
SERVICE WRITER
  • EXPERT
What kind of shape/age is the cap?

A good periodic carbon removing product that I like is "seafoam"

Post a good clear pic of the plug when it gets carboned up.
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Thursday, August 2nd, 2007 AT 5:52 AM
Tiny
DIPWEED23
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To not get the deposits on the spark plugs, make sure that they are gapped correctly, that your cap and rotor are in good shape, and you are using the proper grade of gasoline recomended in your owners manual.
Your timing should be adjustable, so make sure it is adjusted to the proper setting listed on the emissions label under the hood. Check for vacuum leaks, and for worn valve seals, properly functioning EGR system operation, and that your emissions system is operating properly don't forget to check that little PCV valve too.

That's all I can come up with right now for maintaining a carbon free combustion chamber. You can also periodically use a top of the line premium fuel with a high octane rateing, and a fuel addative dezigned to prevent/cure carbon in the combustion chamber.
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Saturday, August 4th, 2007 AT 1:02 AM
Tiny
THIENHAHHG
  • MEMBER
By John Garett

When Karl Benz has been credited for being the first to released the very first "official" automobile that ran on the internal combustion engine, the German-born engineer was most likely unaware that his creation, and name for that matter, would soon become a global phenomenon. A century and three decades after its official start in 1871, Mercedes Benz is now one of the premier car makers in the world, continuing the pioneering spirit of its founder with its successive models throughout its lifespan. Garnering a reputation of never compromising quality and durability, Mercedes Benz has survived two World Wars, in which, the aftermath of both campaigns crippled the local German economy. Despite the adversity, the original vision of Karl Benz persisted, making the Mercedes Benz name famous among the current generation's celebrities by providing sports cars and limousines, all of which have kept the inventive spirit of its creator, changing the automotive industry several times throughout the industry's history. Despite numerous innovations in engineering and car electronics, such as the crumple zones, anti-lock brake system (ABS), PRE SAFE, fuel injection, just to name a few, the Mercedes Benz brand has yet to forget the bare basics of automotive technology. After all, as the company that supposedly started it all, no one understands the importance of the basics of the internal combustion engine like Mercedes Benz. The fact of the matter is, for an engine to work, you need compressed fuel that is combusted and turned into mechanical energy. The key proponent that makes this procedure possible is arguable, but one can never ignore the importance of spark plugs when discussing fuel combustion. Mercedes Benz spark plugs aren't anything fancy compared to the other car manufacturer spark plugs, its still screwed into the combustion chamber, made up of a conductive core inserted in a ceramic insulator.
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Friday, August 31st, 2007 AT 11:02 AM
Tiny
MMPRINCE4000
  • EXPERT
Does the car emit blue smoke on startup? If so the valve seals are bad and will foul the plugs.

The seals themselves are not expensive, but the camshafts must be removed and you need some special tools to remove/install new ones.

I just replaced the valve seals on 2 of my GEO's. I bought a Kent-Moore service kit on ebay for $30.
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Thursday, October 18th, 2007 AT 6:38 AM

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