No start after new cylinder head

[BogusBeefsteak]

Today I got the Aveo two ECUs from a local junkyard. One from a 2004, and another from an equal 2005 LS close on VIN just in case. No dice from either ECU. My next bet would be crank/cam position sensors.

Other question: what SHOULD my compression numbers be?

These are my timing marks


Looks like your bottom gear is a slight bit off from directly aiming down. I can't knock yours if it runs, but for me, that's not even a full tooth of difference.

[xintersecty]

Your timing marks look great. Mine show a slight difference down as I have not put tension on the belt when I took those pictures. When I measured my compression after my cylinder head job, I had numbers around 140. Now I am pulling these numbers out of my head and don't remember exact details.

The cam sensor has gone out on me at least one time. The crank sensor has always been good.

[xintersecty]

Check your cam pulleys do one of them have an I? Also look at my picture of the cam sensor vs your's. Mine is a 2006. I am wondering if that is a model year difference?

[slayerized6]

I recently had the same problem with a no-start condition. Turns out my valve cover gasket was leaking at the spark plug tubes and fouling all my plugs. I replaced my plugs and valve cover gasket and I was up and running again.

If you checked fuel pressure, have spark, and have compression, its not the ECU. Whether the ECU, cam or crank position sensor is dead or not, with all 3 of those, you're going to have combustion. Im telling you, CHECK YOUR PLUGS AND WIRES!

[BogusBeefsteak]

Check your cam pulleys do one of them have an I?

Where would I find that? Also, this was taken with the screen-side camera on my phone. Lost the rear camera. You'll want to rotate your screen (can't write bbcode to save my life) and to me it seems that your cam position sensor is interchangeable. What sort of symptoms of failure did you have when yours went out?

Turns out my valve cover gasket was leaking at the spark plug tubes and fouling all my plugs. I replaced my plugs and valve cover gasket and I was up and running again.

Thanks for the idea! Last week before even thinking about the ECU I picked up 4 brand new OEM-spec NGK plugs. Gapped them to spec - which I think was .044 - then stuck them in. After the new plugs went in it found one cylinder to fire once or twice before going back to cranking. The Aveo has earned itself a new name/badge of honor though: "Almost Works Every Time"

[xintersecty]

My car was in good running order and I got a failure light and a code indicated the cam sensor. If you look on my picture of the cam pulleys there is an I on the intake. I wonder if you accidentally swapped the pulleys.

When you check spark, do you use a GAP spark tester or a sensor around the coil wire?

[avguy]

... Other question: what SHOULD my compression numbers be? ....

When I did a dry baseline compression test on my '05 at 147K miles, the gauge readings for all 4 cylinders were 205-210.