I have a 98 12v and my mods are, free gsk kit, starwheel up some, afc forward and stock plate forward, goerend bros. tranny and tc. Eversince I did the free mods my truck will not idle right. It will either idle too low or too high. I will set is just right and then it climbs up past 1100rpms! So now I have to set it to where I have to put my foot on the gas to make it crank. Is a bad tps possible?
The other problem with the truck is ever since I changed the fuel filter it will some times starve for fuel when I am Idleing. It will cut off and take a while to get it to start. When I changed the filter I did not fill the filter housing with fuel so it took 20 min to get the truck started, I dont know if that would hurt the pump. Thanks and sorrry for the long post

 

the idle problems seem to be due to the free Governor spring washer.
Some trucks just dont work right with it (including my 98) you could try loosening the sping retainer nut a click or two, and then adjust idle screw!
A low idle screw causes the non starting without giving it pedal!

 

thats what i was thinking was those 1/2" washers. I will back those retainers out and if that doesent work Im taking those washers out and getting a real 4k gsk kit with valve springs.