Chevy troubleshooting i have a 2005 chevy colorado that randomly wont start but u wait 10-15 min and it starts up and it idles funny and the code say the fuel trim system is rich iv put a fuel pump, fuel filter, spark plugs, 02 sensors, map sensor, maf sensor and a air filter in it and cleand the throttle body but non of it seemd to work?

. What engine size does it have ? 2.8 or 3.5 l Running rich could be caused by a few different thing's from a leaking fuel pressure regulator to leaking fuel injectors ,coolant temp sensor giving false info to the PCM.Try holding the gas pedal to the floor ,this put's the vehicle in to clear flood mode .If the vehicle does start an run after a bit ,it's not the PCM - engine computer . Don't thing PCM - engine computer problem , running rich . Pull the spark plug's out ,are they wet with fuel ? Black - fouled ?

Clear Flood Mode
If the engine floods, clear the engine by pressing the accelerator pedal down to the floor and then crank the engine. When the throttle position (TP) sensor is at wide open throttle (WOT), the control module reduces the fuel injector pulse width in order to increase the air to fuel ratio. The control module holds this injector rate as long as the throttle stays wide open and the engine speed is below a predetermined RPM. If the throttle is not held wide open, the control module returns to the starting mode.


003 Engine Peformance Tests Scan Data Tests
004 Fuel System Tests Start Here

Had a s10 one time and had similar problems turned out after I got rid of it a friend figured it out it was the computer and the Catalac converter how ever you spell it hope this helps Merry Christmas