I have a 2009 hhr that ive had for nearly 4 1/2 years. Been a great car but I have a mystery. Check engine light came on after I had it for a few months. Nothing seemed to be amiss and the car ran great. Took it on a lot of day trips (400 miles round trip) and with money tight,as long as it ran fine,I left it alone. Well when I finally had some time I checked it with an obd scanner and it shows a p0016 and p0017. Has been 4 years this way and I havent had any problems. When I had the money, I replaced the cam position sensors and I changed both of the cam actuators. The car is still slow to start. Like 2 or 3 key turns to get it running and only after I step on the gas. After its warmed up though she starts on the first turn of the key and have no problems. Its only after she sits for a long period of time like 8 hours or overnight when Im at work, that shes doing this. Any thoughts? If it was a timing chain issue, would it even catch at all? Or given out in the last 4 years?
The next time you go to start the engine after the vehicle has sat for a while, turn the ignition switch to on so the dash lights come on for two seconds, and then turn the ignition switch off.
Repeat this a half dozen times and then try starting the engine.
If the engine starts right up, it points to a problem with the anti drain-back valve in the fuel pump.
Thanks, I’ll give that a try.