Hey i have a 91 chevrolet silverado c1500 with the 350. Ive been having problems with the truck runing like crap, it stumbles and misses and sometimes it will go. Well if i unhook the wire to the distributer ( the one that u unhook to set the timing) the truck will run fine, but the timing only stays were u set it since the comp is not controlling it. ONce i plug the wire back together i can watch the timing with a timing light and the timing jumps all over the place, sometimes it looks like its 180 degrees off. Ive changed the module in the distributer, the little chip thats in the comp. I was wondering if any has run across something like this. thanks