87 300E wont start, I know what the prob. isn't
 

1. Fuel is going to the engine - pump and relay work fine.
2. Plugs are getting spark
3. Engine refuses to start, fuel is present.
4. Compression is great.
5. It's not flooded, I let it sit for a day, manually drained fuel from intake.

So any clues? The spark appered to be random, but only after several tries when the battery was weak, needed constant jump after that to turn over. Thanks in advance.

Exhaust pluged up.
Disconnect exhaust from manifold and see if it will start.

OVP relay or dead battery giving too low a voltage when cranking -- if less than 9.5, no ignition.

Peter