Tricky issue

[Colburn]

I just did a head job on my 04 Aveo because the timing belt went out. After putting it all back together the only result I get when I try to start it is a backfire into the intake. The only thing I could think about being the problem is possibly switching the cams when I put them back in. Would this cause the problem I'm having or would it be something else?

[petrified.rabbit]

even if the cams are not switched, have the cam timing off on them could cause that. if could be that you switched them, it could just be the timing is off. Recheck everything you did, and all the timing marks.

I am not sure there is an easy way to tell the cams apart. I have not seen a set of etec cams, but the "issue" of them being interchangeable seems to have been posted, so i imagine they look the same.

[Colburn]

Rechecked the timing marks multiple times before and after the issue was found and they are lined up perferctly. Thats why this is so baffling to me.

[paulsaveo]

i would recommend doing a cyl compression test

[petrified.rabbit]

if the marks are dead on, then the possibility of the cams being wrong improves, especially because you think that is what you did.

not a terribly hard fix.. but time consuming. And if you have the cams correct now, it could be catastrophic.