My 2006 4 cyl 2.8l standard chevrolet colorado revs up when in nuetral or when the clutch is pushed in (when its not engaged in gear) also it shows no temperature on the temperature guage it also doesn't want to start it will but then sometimes it runs choppy and dies and sometimes it runs fine

SOURCE: temperature guage

Right behind the grill around the rad. support on the passenger side (usually) there is a sensor called an ambient temperature sensor. That gives your outside temp. on your rearview mirror.

SOURCE: 94 chevy suburban revs up and down, then dies

timing chain

SOURCE: I have 2006 Chevy Colorado

There is a recall for valve problems. The warranty for this problem has been extended to 100,000 miles for that. Check with your dealer to see if that is the problem. If no help contact GM.

SOURCE: 2003 chevrolet venture will not start. Was running

You have a shortage or a bad starter. Tighten all bolts leading to battery and starter. If still giving you problems, remove starter take to auto shop have starter bench tested.

SOURCE: Start problem

I have had the same exact problem now for 2 years. I have taken it to the dealer and it never does it for them and they say everything is within GM standards. I read about other gm cars having the same problem and some of them have been lucky enough to fix the problem by replacing the fuel pressure regulator. I am currently trying to see if its possible to replace in my '06 equinox. if you have any news please reply!