Originally Posted by Railrust
I keep hearing...if you have direct injection, your problem is the valves, but I'll tell you...people are having injector issues too. Top tier fuel is all I keep hearing on the GM truck forums...that and Techron. I do the top tier fuel, but not the Techron. That's going to change (having my first injector issue now). Cylinder 5 misfire. -25 fuel trim, loss of fuel economy. Something did this for two weeks. On and off. Intermittent. Pulled the plug, looks good. Switched the coils, still number five.
Seems "ok" now. Keep hearing...run some Techron through it. I'm going to.
I would think a dirty injector would reduce flow/spray into the combustion chamber and would produce a lean condition but maybe you've got deposits/varnish inside the injector that's keeping the injector from closing? Trav would know more about this than i do... but if the Techron doesn't solve your problem, move the injector to another cylinder and see if the misfire follows..if it doesn't, than it's likely NOT your injector causing the misfire. But i would not be surprised if it is...
Btw, Berryman's would also work well, maybe even better, for cleaning up any varnish or debris on the inside of the injector body though that's not to say that Techron system cleaner concentrate isn't a very effective all around cleaner.