I found out something very interesting on my 2007 LS with a 2.2L. It does not have the high pressure fuel pump driven by the intake camshaft. It does however have an electric one near the tank. Was this something GM changed later on? I just thought that it was interesting.

 

The hi-pressure one is for direct injection engines. Our 07's are not direct injection engines. The 2.0 is and the last couple years of the hhr's are iirc. Just not sure when it was changed over.

 

Pretty sure only the hhr SS have it, the newer 2.4 DI engines started in 2010 but in the Equinox.

 

I think you are correct. While I can find the sidi used in other carsit was not used in ours before they were shelved.

 

They are direct injected. If you look the injectors go right into the cylinder head. They have the heavy gauge fuel rail and no pressure regulator on the fuel rail. If you go back by the tank the high pressure pump is back by the tank. I just wondered when they changed over to the mechanical pump. I haven't had any problems. but i just wondered if they switched because they had problems with the electric high pressure pump.

 

The tooth fairy made the decision for the change.

 

As with all automotive engineering. Sometimes it just happpens. I have to say. This is absolutely the most reliable car I have ever owned. I took the spark plugs out to change them at 102000 miles and looked at them under a high microscope. The center electrode was still completely square. I have replaced the brakes, shocks and struts and a catalytic converter and that is all and I have got over 150000 miles on it. it has never broken down. I am sold on GM reliabillity.

 

No offense ment here but you need to do some research on this yourself and LEARN about direct injection. Direct injection has the injectors fire DIRECTLY into the combustion chamber and not in any part of the runners regardless of the runner being in the intake manifold or the head.

SIDI is what GM calls their DI and it is not found in any of the ecotecs that were used in NON-SS HHR's. Look it up and you will see this. I had to do this to refresh my memory .

Also DI uses much more PSI then 50-60 like our motors do. Thus the need for the second HIGHER pressure pump. The one at the tank just gets the fuel to the engine bay then the second pump force feeds it into the injectors. It can reach into the low 2000PSI range with this second pump.

Here read this article from when SIDI was first introduced. Which just so happens to be 2007. BUT not in the HHR until the 2.0 Turbo motor was added to create the SS.

http://www.atraonline.com/gears/2007...2007_11_18.pdf

 

No offense taken. I am familliar with the concept of DI, but I think I was definitely mistaken here. I assumed that the injectors on the '07 ecotec 2.2L were in fact going into the combuston chamber. It would be evedent then that they go into the intake port, but in the head and not the intake. I also assumed that since there was no vacuum operated pressure regulator that this was a DI fuel rail. Sorry about that. Did not mean to spread mis-information. That is correct then. '07 non-turbo= regular old PFI.

 

Aside from the SS's, all year LS and 1LT/2LT's were normal FI.