I have a 2008 Colorado with a 4 cyl. engine and 110000 miles. When driving it somewhere I shut it off and when trying to leave it won’t start up right away. After waiting 15 to 20 minutes it will start up. My mechanic has checked everything and seems to think it is the starter but says there is no way to check it, Repair bill quoted at $530. Any thoughts on the problem?
Find another mechanic, this one doesn’t know what he is doing. If the engine cranks, the starter is NOT the problem. Ask friends, check Yelp, and the BBB for a good independent auto shop.
I’d guess the fuel pump check valve is bad or the injectors are leaking. Next time it fails to start, turn the key to ON but not start. Listen for a hum from the rear from the fuel pump. cycle the key off, and on 3 more times. If it starts right up, I’d be planning a fuel pump replacement.