My 850 still will not start! Help please

[rmburns18]

This is my original post-

I have a 1996 855 non turbo with 200k. it has been running great and on thanksgiving going up a mountain in north carolina cel started flashing and was throwing codes po 300 303 304 and 305. it quit running and now wont start. I replaced the fuel pump relay. And can hear the fuel pump running when the key is turned on. It has bee throwing cod po 172 the last couple of weeks every 100 miles or so.

I since have Replaced:

Battery
Ignition coil
cam sensor
coolant sensor
plugs and wires
dist cap and rotor
fuel filter and
fuel pump
crank sensor
drained the fuel tank and replaced fuel

I have checked compression and great compression on all cyl.
also checked to see if timing belt had jump-- it didn't
I am now at a total loss.

[chuckcintron]

Time to get back to basics. For your car to start you need three things:

-air
-fuel
-ignition

Actually four things if you include the energy required to get the crankshaft turning (i.e. battery and starter motor).

Check each of those three delivery systems (air, fuel, spark) and let us know which one(s) are not participating.

-Chuck