It seems that the cold idle is too low upon start and thats why if i turn on the ac the knock goes away. funny thing the hot idle is too high, i have the hot idle a bit high because the alternator doesnt charge well so the idle got turned up to charge better.The timing is done on a denso rotary injection pump fully mechanical. How can I adjust the fast idle, which is the cold idle? How can I check the glow plugs? Could it be a fuel pump issue? I am going to send this video to a mechanic and see what he says.
The fast idle is the idle when the vehicle is cold. If I am not mistaken the fast idle is set at a higher rpm than the regular idle?