Toyota Repair: timing issue, cylinder head gasket, haynes manual

Question
hello there. it feels good to be able to ask you a question. ive been waiting for a week now to ask you about my car problem.. anyway, i have an 1984 2.8 inline 6 toyota supra. this is my hobby car and its just been seating at my garage for couple years now. i do a little this and that to make it race and show car. i sometimes take the car out for a spin just to give the motor fresh air.. i changed my cylinder head gasket and at the same time i installed a new timing belt. i have that haynes manual and i followed their step for doing tdc and aligning the camshaft to the timing plate mark. i also did the distributor installation according to the manual. when i start it fires right up. i let it warm up for a couple minutes then i hook up my timing gun. i made sure vacuum line is all connected and my rpm is like 700 800.. i jump the check connectors together according to the manual but when i check my timing its pass 15degrees and thats the farthest the numbers goes to. to be excact it looks like 17 degrees. i tried adjusting the distributor up and down but nothing close to 12degrees which that car calls for. when i get to the lowest point that i can there is no power when trying to drive.i tried so many variations with the installing of the distributor but nothing. double checked all my belt. the tension, the marks.... nothing. i really want it to set at 0degree. ..... when i drive it at 17 degrees setting,the car makes like a knocking sound pass 3500rpm.. i guess thats because the timings to high? what can you suggest me doin. ive been trying for weeks now. please help.......

Answer
The timing should be set at about 5 degrees advanced at idle with the check connector in place. If you are not able to get to this setting then there are only two possible causes, either the distributor is not timed correctly or the belt timing is off, I know you said you rechecked this but there may be something your'e missing. Remove the top part of the timing cover and rotate the engine to #1 TDC, check the timing marks of the cam gears with the marks on the inner cover. also make sure that the camshaft locating pins are in the middle hole of the gears, there are three holes in the gears. That's about all I can think of right now, please follow up if there is anymore I can help with.