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10-4. I think what my ultimate question was, if I had to replace an injector would I be better off just getting one to match the other 3 or replace all 4 with an upgraded version? (As in reference to this entire thread)
I started this thread because I believe that the injectors, or my professional opinion is changing to recognizing it might be the car has a design flaw due to lack of post pump fuel filter with tiny orifice injector, that causes a fault.
I cannot tell you what to do, but I give you my opinion:
replacing one injector with a type prone to failure may lead to continued failures, it is probable you would need to do all 4 or you will get an injector balance issue off the bat.
You could add an inline filter and maybe the stock injectors will prove more reliable, but you likely still need all four injectors as they do not clean well.
You could follow my lead and get the same parts number I have tested and recommend, and likely car will run fine forever more. Feedback from another tester would be welcome, whatever your result may be.
One detriment of the alternate injector is they may not atomize as efficiently. Notably the surface area of a particular fuel passing though 4 holes vs 12 holes would be slightly different, You might see a very slight drop in MPG compared to stock in perfect working order.
I suggest the injector I do if you are unable to tune.
If you ARE able to tune, You have MORE options. I think the 09-11 injector may be a best choice, it has larger holes but is 12 port and gives a more optimal atomization, I am redoing to math to support or refute this in the next 24 to 48 hours.
Yes, I would like to learn to tune upon conclusion of this test, and explain my story more fully.
As for part acquisition, I have near unlimited yards to wander through, so finding these injectors just took time, there are more out there. Uncertain if you are able to do the same, or willing to try used parts.
Of note, most "rebuilt injectors" are just cleaned injectors that have been run through a machine with cleaner, plus new O-rings added. No new internals.
My C1500 was originally a 305 cu in with a 2 bbl TBI , I upgraded to a 355 cu in still a 2 bbl TBI but a modified version, larger diameter throttle body plates and bored venturis a 255 GPH fuel pump, stainless steel fuel lines and I installed an inline fuel filter between the tank and TBI, it increased HP but wasn’t very much of an improvement in MPG.
Still a nice truck. I keep an eye out, maybe I will find one.
So I made some simple tools. These are go/no-go gauges. You can determine the relative size of a small hole. I don't have one for ever step (ie, every .0005")
I can organize the injectors I have on hand now by orifice size.
More math later. This took me longer than I wanted.
Also quick compare
Vehicle Model Combined MPG Highway MPG City MPG
2011 Automatic 4-spd, 4-cyl, 2.4 L 24 29 22
2010 Automatic 4-spd, 4-cyl, 2.4 L 25 30 22
2009 Automatic 4-spd, 4-cyl, 2.4 L 24 29 22
2008 Automatic 4-spd, 4-cyl, 2.4 L 24 28 22
2007 Automatic 4-spd, 4-cyl, 2.4 L 23 28 21
2006 Automatic 4-spd, 4-cyl, 2.4 L 23 28 20
Vehicle Model Combined MPG Highway MPG City MPG
2011 Automatic 4-spd, 4-cyl, 2.2 L 24 30 21
2010 Automatic 4-spd, 4-cyl, 2.2 L 25 30 22
2009 Automatic 4-spd, 4-cyl, 2.2 L 25 30 22
2008 Automatic 4-spd, 4-cyl, 2.2 L 25 30 22
2007 Automatic 4-spd, 4-cyl, 2.2 L 23 28 20
2006 Automatic 4-spd, 4-cyl, 2.2 L 23 28 21
from https://www.officialdata.org/cars/Chevrolet/HHR%20FWD
I note that it appears that the 06-07 get slightly worse fuel mileage than do other years with same powertrain. However I don't have Final Drive Ratio data for the automatics which could affect those numbers if it was changed. I did find manuals had their FDR change over the years.
Assuming that FDR did not change over the years, then the injectors I installed may be performing more like the 08 injectors in performance. EDIT: I mean the 06-07 injectors may not be as efficient as the other injectors leading to the differing economy numbers, pending FDR infomation.
Following an alignment, I got around 31 MPG in the car with solid highway cruising varying between 60 and 70mph. Not bad!
Last edited by Rocket Surgeon!; 01-16-2021 at 02:25 AM.
This eliminated FDR at least with respect to changes in fuel economy. Stock tuning is a remaining possibility. However, fuel mileage is still really good at 29mpg after some city driving.
Thank you Brain Scientist! for your hard work and due diligence
Have installed on your recommendation
12582219 4pcs/lot Fuel Injectors for 2005-2010 Chevrolet Cobalt 2.2L 2007-2010 Pontiac G5 2.2L 2005-2006 Pontiac Pursuit 2.2L L4 2171634
Car 2007 premier edition 2.4 seems to have woken up engine response was very good for an around the block spin
next on list is four 4T45E solenoids when I've got it back together updates on highway mileage and overall impressions 2007 premier
Last edited by Murph; 03-09-2021 at 10:29 PM.
Reason: Add picture
You also need to look at ignition systems. The early models had lost spark ignition (2 coils). The 2008 2.2L went to coil on plug (4 coils). I'm not sure about 2.4L.
<Regarding mine>
Mileage is lower when GF drives. but she idles a lot and goes through drive throughs way too much. Car continues to run well, though I need to do more work on it still.
Last edited by Rocket Surgeon!; 03-10-2021 at 11:49 PM.
01-12-2021, 12:23 PM
