You say "not flex fuel" like the computers are the same. Do you think no adjustments are made depending on alcohol content?

Oddly, the link provided went to specifically LE8 eighth digit W. They make it difficult to choose the wrong engine.

 

Ok so when turning the key and letting it crank on its own all four cylinders were between 155 and 160 psi. When holding the key over all cylinders maxed at 210 psi.

When we replaced the plugs, the ones we pulled out were AC Delco 41-988. Those are listed for an HHR but not a Cobalt. We put in the ones you listed - 41-103. We also replaced the purge valve.

So far no difference and still have the P0301 code.

We are going to hook up the scanner tomorrow and see what it's reading. He's got one that shows more detail than just the code. We have to get the tool to do the leak down test.

Thanks,
Jessica

 

41-103 is for all HHR except some 2006 2.4L and SS. I got no idea where 41-988 came from

The engine is a 2009 Cobalt, you should use Cobalt engine parts. However, 41-103 is correct for your Cobalt engine.

Don't bother reading the diagnoses or description of any code readers built in stuff.

I don't understand your first sentence of #32. Are you doing fuel pressure and compression at the same time and mixing the data?

 

No, just the compression test. We unplugged the fuse and relay for the fuel pump so it wouldn't start, took out a spark plug, and screwed the tester into place. Did we do it wrong?

Thanks,
Jessica

 

Nope, good compression. Let’s move on to the fuel pump pressure test.

 

We did a fuel pressure test last week. Is that the same as a fuel pump pressure test? It was around 60 psi while running but 0 psi with key on engine off. I read somewhere else in this forum that <Fuel pressure per the manual 50-60psi "key on - engine off".> I can't find my owners manual to confirm that and the one I downloaded didn't have it listed anywhere.

Thanks,
Jessica

 

If I remember correctly (I have a bunch of different vehicles so I hope I'm remembering this for the HHR!), yes if you turn the ignition on without starting the engine the fuel pump will run. This is done to pressure the system before starting.

Also on some vehicles there is a different relay for the fuel pump during the "prime during ON" and for the pump after it is running.

Oldblue or donbrew can verify or negate what I said.

I don't have my HHR factory manual here so I am flying by memory...

Steve

 

Owners manual doesn't show fuel pressure specs.
If you need a copy of the Owners Manual, they are available for download on this site. Donbrew even has a link to them in his signature (although no one ever seems to notice the link )
{You'll need to click on the link in one of his real posts since the pic below is just a screenshot }

 

Fuel pressure should be as follows per Donbrew in a thread in 2019.

Start engine, stop engine, pressure should read 50-60 PSI, if it drops more than 5 PSI in 1 minute you need a new pump. Should never be zero.

 

Ok we can do the pressure test again. I'll see if he can bring it over tonight.

And Yes firemangeorge, that's exactly where I downloaded the manual from. Well from the other post it links to. LOL But that comment about what the manual says was from another post on here. https://www.chevyhhr.net/forums/prob...61/#post706721 That's what we were expecting.

Thanks
Jessica