Changed out crank position sensor on 2006 hummer h3 and continue to run rough and sputter at idle

SOURCE: 2006 H3 Hummer AC/Heater Fan Motor

I brought my 2006 H3 in to the dealer for the same thing. My blower stopped working all together but it started as an intermittent problem. He said he had to replaced a diode or resistor either behind the switch on the dash that controls the fan or on the fan motor itself. Have not had a problem since but that was only about 4 months ago.

SOURCE: 93 Nissan Altima idles rough and has no power.

check exhaust back pressure . can have no more than 2 to3 inch pounds off pressure. may also want to check timing marks.

SOURCE: 2006 Hummer H3 fails to start periodically

If you look in the owner's manual it will explain this. Happened to me a bunch of times, really embarassing. It is an additional anti-theft device . If the computer senses that the key is inserted improperly, or that it is not a perfect match for the code it has in its memory for your key, it shuts of the gas supply to your engine for approx. 10 minutes to defer theft. Still happens to me intermittently. Now only very rarely. Total pain. I cleaned my key..carefully, with WD40 and after drying put just a touch of graphite on the key and started the beast a number of times. My dealer didn't read the manual either. You must wait the full ten minutes before trying to restart....otherwise it never totally resets and (the first time this happened to me) you can sit there and fight it forever.

I don't have my owner'smanual handy to refer you directly to the proper pages, but its in there under theft deterent. Hope this helps......and that Hummer can provide aneasy fix for this.

SOURCE: where is the MAP sensor on a 2006 Hummer H3

Its located on the drivers side of the engine,mounted on the side of the upper intake plenum.

SOURCE: 2002 chevy trailblazer has rough idle

There are numerous things that can caise a vehicle to idle rough. Could be a throttle posistioning sensor. pcv valve, dirty fuel filter, worn spark plugs and wires, possible O2 sensor. If the vehicle has not had a tune up yet, I would recomend one. Even if it doesn't fix your issue, the vehicle is ten years old and probably needs on anyways. Start there, then rule out the cheaper stuff next. pcv valve and fuel filter, inexpensive and it's probably time anyways. If you are getting an engine code, stop in to advance auto. They'll plug it in for free. If your still having problems, you may have to break down and tajke it to a mechanic to get plugged into a real diagnostics machine.(probably run you around $100)