Bought a non-running 1991 740 230 turbo with 115,000 miles. The previous owner over-heated the car to the point that the head was warped and later found one exhaust valve was burnt. Replaced timing belt, water pump, milled head and new exhaust valve. Car will start but only after lots of cranking if it starts at all and sometimes only by disconnecting the fuel injectors @ the injector electrical plugs the cranking for a while and re- connecting injectors. The spark plugs are wet (fuel fouled) and compression was about 75 psi +/- 8 cold on all cylinders (is that too low for a turbo engine)? Once the car starts it runs real bad (no power) until it warms up then runs ok. Hot starts are good. Seems to me there is too much fuel at start and flooding the engine. Spark at plugs is good. Check engine light came on once squawking o2 sensor (cod 2-3-2). Can O2 sensor cause this? The only thing I haven’t checked is timing cold.
What would cause too much fuel at cold start? Anyone have any idea?

Thanks Maurice.