A couple days ago I noticed my Hhr not firing up as it has always done. When I turn the key it does 3 or 4 things in no particular order . First it starts right up no issues. Sometimes it will try to start and do a very short turnover and fizzle out meaning it stops turning and does not start. Sometimes you will turn key and it just does nothing . NO sound won't turn over or anything. Here are some facts I do hear the fuel pump when I try to crank it and it does try to crank, I do hear the air flow sensor click when it cranks or tries to crank. It does run very good when it does crank and does not shut off or run funny and once it runs there is no other issues until I turn it off and at that point maybe it will crank right up or maybe it will do these symptoms mentioned above. All I know it its getting worse. I changed spark plugs today and it cost me 30.00 I figured I would ask you guys before I bring it to the dealer for a diagnostic.
I have a 2007 2.2 ltr Chevy HHR 4 door LT

 

My guess is the run/start relay is either loose or failing. Maybe, the 4 bolts in the under hood fuse box need gorilla tightening.

 

Welcome to the site!! X2^^^^^

 

Scan for codes. WRITE THEM DOWN. Post here. The numbers. Ignore the descriptions.

How old is the battery?

Has the ignition switch recall been done?

 

You said nothing about the state of your battery.

 

No mention of any codes, but worth mentioning.