If I set the timing on my 87 22r at 12 degrees with the vacuum hoses attached,and rev the motor to 3000 rpm,should the timing move up or pull down to 0 degrees? I'm trying to figure out why I lose power from around 3000 rpm and up,thanks

 

the timing should advance under high-vacuum/part-throttle conditions and retard under full throttle conditions up to the point where the total advance of the centrifual advance mechanism has been reached.
It should not ever go to 0 degrees... it should not drop below the initial advance setting.... unless you have knock sensing involved and then the knock sensor could cause the timing to drop below initial advance.

 

I can set the timing on 0 with the lines plugged,then connect the lines and its around 12 degrees,but under any throttle it drops to 0 degrees,the truck pulls fine till around 2800 rpm and up the just seems to lug all the time,any ideas on what to try?thanks

 

it was the port on the carb causing the problem,I put a vacuum guage on it and it was screwed up,I changed to another port that advanced the timing with the rpm's as it should and the truck scats now