I have an 02 Sub 4x4 with 110K on the clock. I've had a problem for several months with it bogging, then stalling only to start right back up and not have any issues. It never threw any codes and the fuel pump has always been running. Hot or cold doesn't seem to matter.

Recently, it was trying to stall out when I parked it two months ago. All attempts to start have been unsuccessful ever since. Fuel pump is still running with fuel pressure on the rail.

I'm assuming that it may be the crankshaft or cam sensor from past experience with other makes and models. Is there any way to test for a fault with these sensors if they aren't throwing codes? Would they normally throw a code in a GM? I've tried numerous searches here on the forum and haven't found an answer yet. I've explored the fuel related issues and don't think that the problem lies there. Anybody have any other suggestions or ideas?

 

You should first see if there is spark, fuel(are the injectors firing?)and compression.