I was told the Powerpuck on 98.5-2000 model trucks added timing. Well I got mine in the mail today and it piggy packs off the Injection Pump which I would think would add fuel instead of timing?

 

i must change timing.. because i bought my truck and didnt know it had a powerpuck on it.. and went ahead and bought an Edge comp box.. well, when i got it all hooked up, i saw that other chip... lol well, i tried to stack them.. and there was no way.. they did not work together.. the engine shifted weird and sputtered and rpms were jumpy.. they have to both be timing boxes for that to happen.

 

my Van Aaken is also a timing box that plugs into the injector pump like your power puck, the newer VA's plug into the data link & the map sensor, like most of the power puck's I've seen do, but it is only a timing box if it does not tap the injection pump wire, with the exception of the smarty which is a totally different animal!! LOL