E30 Starting problems... 1990 325is ???HELP???

[victorcleaner]

The 1st really cold day (around 10 degrees F) here in CO, seemed to render my car inoperable. Please help???
The 1990 325is (130k miles) has, in the past few years, tended to start harder in the winter, and also if it ever stalled just after starting, while the engine was still cold, in any season. But no fault codes at the 5 pedal check, or on a code reader.
I replaced my plug wires (with Bav-auto Perf. wires), plugs (Bosch Super Plus/gapped properly at 0.028"), cap, rotor, timing belt, all radiator hoses, coolant temp sensors, thermostat, fuel filter, air filter, oil filter, oil (Lubro Moly Voll-Synthese) and the water pump which was also leaking at the time, about 3 years ago, but with little improvement to the starting issues.
For the most part, the starting problems rarely occurring badly unless it was very cold out, so i just figured my air mass meter was eventually due for R&R.
A over a year passed by and the bav-auto perf. wires began to malfunction, and the life-time warranty replacement went very smoothly, noticing much needed improvements to the redesign of the updated version when they arrived. I also changed the plugs again with the replacement wires at that time.
Tried starting her last week now and she wouldn't even seem to fire until the battery completely gave out. Charged the battery and figured i needed to address the air mass sensor, which also seemed to be causing a lag in throttle response, lately. So, i ordered a rebuilt (Python) AMS from Amazon for $140, and also obtained a Signature Motoring heat-shield and K&N cold air filter for about another $150 to replace the OEM air filter box. Cleaned the ICV out as described with carb-cleaner and it spins up fine without a history of idle fluctuations. Also replaced the intake boot, ICV hose, and crankcase vent hose... when i did the CAI upgrade.
As it turned out, the car still didn't fire even as the temp increased a week later; so i placed another order for a new coil, plugs, and a pulse sensor.
Just finished that job last night, and still no success...
Spark test shows that a hot blue spark with ignition, and gas is smelled as though it floods after cranking to no avail... but still no firing.
I haven't done a compression check yet... but have started to think it's about time to replace my main relay, fuel pump relay, and OBC relay.
Besides, a long since past history of hard starting, this problem is very sudden... and she has been running like a top, otherwise.
No code faults, and after i R&R the relays... i'm running out of ideas???
Besides the Motronic ECU... which seems to pass the code checks, i've practically replaced the entire ignition system over a short period of time.
I've also heard the OBC can security lock the engine from starting...
I'll be replacing the fuel filter tomorrow too, since that should also be over due by now for R&R. Fuel delivery and compression are all i can think of after that.
Any helpful suggestions and ideas would be greatly appreciated...
(as i'd rather not pay for a flatbed tow to the nearest dealer who charges over a $120 an hour for labor out here.)
Thanx

[Silvercat]

So 10 F is cold. What is the oil spec? You don't really describe the starting problem. Is it cranking over fast or slow. The wrong oil and a tired battery could be the cause? I've no experience of starting problems on the BMW, but living in Finland I know what the wrong oil and a bad battery can do.