timing advance
 

I have a '85 Silverado with a 305. do these trucks have a electronic timing advance, or vacuum timing advance?

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'71 Custom 10 lwb

They have both mechanical and vacuum advance. They also have what is called an ESC (Electronic Spark Control). The only thing the ESC does is control spark knock. You notice the distributor plug has 4 pin plug on it.

It also has a knock sensor in the engine block (in front of the starter). When the knock sensor detects spark knock it sends a signal to the ESC contoller (mounted behind the glove box, above the heater). The ESC will retard the timing to stop the spark knock.

As a side note, I have removed all that mess on my 85 C10. I installed a MSD Pro-Billet HEI.

Hope this helps,


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Mike

1985 Chevy C-10
Mike's 73-87 Chevy Pickup Site

Thats what I'll be doing on the '81 when the 305 blows, or I get tired of it and use it for demo usage.
This ESC is odd....