Big_Daddys_Caddys

Got this truck not long ago and it needed a new transmission. It started fine and idled great before I got it but couldn't move because of the transmission. Meaning we never ran the engine for any real length of time, it never really got hot and there never was any day-to-day start-it-stop-it, go-here-go-there thing happening. Once we swapped in a used tranny, when we started running the truck for longer periods, that is when the start-stall issue began. All of the posts led me to the Passlock issue, because it is exactly what the passlock security does: Starts the engine, runs for a second, then just dies. So it was OBVIOUS! HOW COULD IT BE ANYTHING ELSE??? We jiggled wires, we looked for weak connections, we checked voltage & fuses, we thought of changing the tumbler, the key, even over riding the passlock system --- Then --- we opened up the air filter housing to get to the air intake for a throttle body clean out ---> It was the Sahara desert in there. Sand, dirt, sh*t, you name it, all there. Cleaned everything out like a surgeon ---> hasn't done it in two days! Moral of the story - Don't get too locked into pursuing ONE solution, even if the internet says so. They can be wrong. Thanks for all of your help guys, I hope this post will serve someone in the future.

Thanks for the reply Sefiroxx, on older models of cars/trucks I have seen, there was a separate IAC unit with motor & rubber round tip that would open/shut for more/less air mix. They would get cruddy and would need a good cleaning every so often. On these throttles is there any such separate unit or passage that may need to be cleaned?

Thanks for the reply Riverbanks, just one thing: in the world of cars, I have no idea what a rub spot is and does...

Both.

Hi guys, I'd need a bit of help here please: An '05 6L, when cold and it has to start on the fast idle, it will turn over and run just fine. (99.9%). And (intermittently but often enough) once its warm, it will start, run for a second then stall right out. Exactly like if it had set off the Passlock system but the Passlock security light acts normally and doesn't flash or stay on. It doesn't hesitate, or buck on its way to stalling, the needle just drops like a rock. Also, it has no Check engine codes. When the truck is running, everything about it seems just fine, no hesitation, no bucking, great acceleration, smooth as silk. I would be inclined to check the Idle Air Control valve but I'm not even sure if it has one or not but for some reason I really think it is a security issue that is preventing the truck from running normally because when it does operate normally, it sounds great. Thanks for any help you could offer.

Any update from anyone?