This is my friend's 2001 Pontiac Montana that i have been working on since last summer. It is a never ending PROBLEM.
I fixed the rough idle by replacing the crankshaft position sensor. It now idles great, but until it hits around 160 degrees for the first time of the day. This video shows how it runs.
http://www.youtube.com/watch?v=YJd2amIjEp0
Now it only runs like this when it sits around 8 hours or so. It can sit for 5 1/2 hours and still crank and run fine. So there is something different between 5 hours and 8 hours which makes it run like crap.
Things that have been replaced:
-spark plugs and wires (when this similar problem started a year ago)
-ECM (3 weeks ago,used from chevy venture, only did relearn and it works, no reflash)
-TPS ( 2 weeks ago brand new)
-Fuel Pressure Regulator (3 weeks ago brand new)
-coil pack ( 4 weeks ago, used from chevy venture)
-module ( 4 weeks ago, used from chevy venture)
-both Crankshaft Postion Sensor (2 weeks ago, brand new)
-Catalytic Converter (5 weeks ago, brand new)
Tested:
-MAP sensor (last week, GOOD)
I fixed the rough idle by replacing the crankshaft position sensor. It now idles great, but until it hits around 160 degrees for the first time of the day. This video shows how it runs.
http://www.youtube.com/watch?v=YJd2amIjEp0
Now it only runs like this when it sits around 8 hours or so. It can sit for 5 1/2 hours and still crank and run fine. So there is something different between 5 hours and 8 hours which makes it run like crap.
Things that have been replaced:
-spark plugs and wires (when this similar problem started a year ago)
-ECM (3 weeks ago,used from chevy venture, only did relearn and it works, no reflash)
-TPS ( 2 weeks ago brand new)
-Fuel Pressure Regulator (3 weeks ago brand new)
-coil pack ( 4 weeks ago, used from chevy venture)
-module ( 4 weeks ago, used from chevy venture)
-both Crankshaft Postion Sensor (2 weeks ago, brand new)
-Catalytic Converter (5 weeks ago, brand new)
Tested:
-MAP sensor (last week, GOOD)