97 Sunfire stalled and won't start

97 Sunfire stalled while going 40 mph it cranks over with no problem but will not start. Replaced fuel filter, checked fuel pump, verified fuel to injector rail, replaced fuel injection pressure regulator, all four plugs have spark, removed valve cover and the valve train appears to be functioning properly when the engine is cranked over. I did not do a compression check on the cylinders but while checking the spark on the plugs verified some type of compression from each spack plug port. Any thoughts would be greatly appreciated, thanks.

Codes? It just died with no warning what so ever?

That is correct the engine just stalled and never started again, very strange. I plan on borrowing an OBD II code reader to see if any codes are available.

Connected Code Reader to OBD port and verified no codes being stored in the computer. Compression check idicates no compression on all four cylinders.

no compression... well there it is

No compression on ALL 4 cylinders?!? Are you sure you did the test correctly? I would say that the timing chain broke, but you verified that the valve gear was working correctly?:dunno:

My thoughts are the chain is not broke but has jumped on the cam gear some how and the timing is off so much that it has affected the compression. The compression tester is brand new from Sears and if I put my finger over the spark plug hole there is some pressure but not enough to give me a reading on the gauge. When I pulled the valve cover off all intake and exhaust valves were moving up and down so the chain can not be broken. Maybe this weekend I will pull the timing chain cover off (not looking forward to it though).

fuel, spark and timing. One of the three is the cause. u may want to check the timing belt to see if it is on the mark. it the belt jumped it will not start.

Then check the rail pressure.

Just my thoughts.

I'm going to pull the timing cover Sunday and post the results of what I found. Thanks goes out to all who posted.

I really doubt the timing chain jumped on the sprockets. Try pulling the valve cover again and watch the valve movement while looking down into the spark plug holes as you turn the engine by hand. You'll be able to see when the #1 piston reaches TDC and then be able to watch the sequence from there. If things look good I would try that compression test again. Perhaps the tester is bad.:dunno:

Like I mention before Sunday was the day for pulling the timing cover. What I found was the timing chain tensioner had basically exploded and the chain had jumped on the cam and crank sprockets. Guessing on the degree of off timing I would say around 145 degree off.

After replacing the tensioner and re-aligning the timing marks on the sprockets I buttoned everthing up thinking the vehicle was know operational. Turned the ignition and the vehicle would not start. I rechecked the compression on the cylinders and had no compression on all four cylinders. It appears the valves were damaged when the timing chain jumped timing. I will have to pull the head to really verify this.

Wow, that sucks. I was really hoping you were wrong about the chain because of the possibility of engine damage. At this point I would expect to have to overhaul the engine if the valves did hit the pistons. Tough break. :frown::shakehead

Pulled the head this morning and found all four exhaust valves were indeed bent which = 0 psi compression.

ah yes, god bless interfering engines

Installed rebuilt head and all is good...