GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hi there Geoff, I am Cam.I am not sure if you have used our service before or not. The experts here are third party contractors. Myself, I am a GM technician in a Gm dealership. I will be happy to help you. Please understand that my only compensation for the time spent helping you is by your rating of my service in a positive way. The more information you provide, the better the chances of getting your issue resolved. Also please reply if you have any followup questions.
So about your vehicle, I would be concerned about the connector for the crank shaft position sensor or the camshaft position sensor on the front of the engine. Did either of those come loose or have any wiring issues there? "Are you also able to scan for codes?
Does your scanner show engine rpm?
Because the computer controls everything and it needs to see an engine speed signal. I believe we're going to find something is pinched or disconnected somewhere surrounding the water pump replacement. If the RPM is registering in the computer, and we could be looking at a few injection control module issue. If you crank the engine for 15 seconds and then scan for codes, do you get anything then?