Maybe some of you have run into this before. When my truck is cold, it likes to hang at higher RPM's. One time it nearly stopped idling while I was letting it warm up, then the RPM's came up & it sort of saved itself. When it's warm, it can't seem to idle consistently. It goes from about 500-750RPM and feels a bit rough. It's mostly stock, but I have had a TBI spacer on since last year. This problem started this summer. What I've tried so far: Spraying brake cleaner near the base of the TBI, suspecting a bad gasket. Didn't change the idle. Swapping out MAP sensors. Replaced a cracked/rotten vacuum hose. Inspected the throttle cables. It does seem that they are not closing all the way when it's cold, hence the hanging at higher RPM's. I'm not getting any trouble codes whatsoever. Thanks for any advice!