swarthyfellow

I helped a buddy replaced a cylinder head in his 97 f150 and after doing the job its running but not good at all. Got a CEL for 02 sensor errors and replaced them. Still not running right, checked the compression and apparently all cylinders on that side of the engine have no compression (I didn't run this test myself). Is it possible for the timing chain to in an orientation that this will occur? The motor turning over smoothly by hand after setting the timing and I set it the same way i had before. I have done this job a few times have have never had trouble setting the timing. Let me know what you think