E34 M50 crank but no start

[Kainemoistus]

My e34 m50b20tu decided not to run anymore.

A little back story.
Since the car is put away in a garage fir the winter, i thought id go and let the engine get warm. Fired the car up and it sounded like it was running on four cylinders, okay yes there was no fuel so i came back another day with 10L of fuel. But then discovered the battery was dead. Bought a new battery and started to crank and crank and crank. And from that night on the car hasnt started.

Spark is good, i have fuel and also air, good compression. No EWS since its a 94.

Replaced things as followed:
Fuel pump
Fuel filter
Camshaft pos.sensor
Crankshaft pos.sensor
Both water and coolant sensors in the block
Spark plugs

I have checked every ground the car has. Tried with and without MAF. Poured new 98 fuel in it, the most premium we have in Estonia that we use with old cars. Tried a different ECU with no luck.

Fuel reaches the injectors and they spray nicely and in the same pattern.

Tested compression, everything is good.

Took out the fuel pump fuse, let the excess fuel vaporise and then poured a bit of oil into spark plug holes since i flooded the engine a bit so the cylinder walls were washed dry of the oil thanks to gasoline. Then let it crank a bit to make a little more compression. Still nothing.

And the car just wont start. Any ideas on where i could start looking for more? Theres no chain rattle, so i dont the the chain jumped and caused a timing error.

[dannyzabolotny]

I've encountered this issue with other BMW engines, and it was usually a timing issue. I know it's a bit of a crazy idea, but pull the valve cover and borrow some M50 timing blocks to verify that the engine timing is correct.

Also, you mentioned that you replaced the crank sensor, did you use an OEM part? I've heard of new sensors being dead before, and aftermarket sensors don't always seem to work right in my experience.

[Sleepyhead97]

My e34 m50b20tu decided not to run anymore.

A little back story.
Since the car is put away in a garage fir the winter, i thought id go and let the engine get warm. Fired the car up and it sounded like it was running on four cylinders, okay yes there was no fuel so i came back another day with 10L of fuel. But then discovered the battery was dead. Bought a new battery and started to crank and crank and crank. And from that night on the car hasnt started.

Spark is good, i have fuel and also air, good compression. No EWS since its a 94.

Replaced things as followed:
Fuel pump
Fuel filter
Camshaft pos.sensor
Crankshaft pos.sensor
Both water and coolant sensors in the block
Spark plugs

I have checked every ground the car has. Tried with and without MAF. Poured new 98 fuel in it, the most premium we have in Estonia that we use with old cars. Tried a different ECU with no luck.

Fuel reaches the injectors and they spray nicely and in the same pattern.

Tested compression, everything is good.

Took out the fuel pump fuse, let the excess fuel vaporise and then poured a bit of oil into spark plug holes since i flooded the engine a bit so the cylinder walls were washed dry of the oil thanks to gasoline. Then let it crank a bit to make a little more compression. Still nothing.

And the car just wont start. Any ideas on where i could start looking for more? Theres no chain rattle, so i dont the the chain jumped and caused a timing error.

Any cel? Mine did this... It was the maf.

[BrandTurbo]

I've encountered this issue with other BMW engines, and it was usually a timing issue. I know it's a bit of a crazy idea, but pull the valve cover and borrow some M50 timing blocks to verify that the engine timing is correct.

Also, you mentioned that you replaced the crank sensor, did you use an OEM part? I've heard of new sensors being dead before, and aftermarket sensors don't always seem to work right in my experience.

Since you mentioned this was usually timing related, I hate thread hacking bro believe me lol. Just picking your know how. With the valve cover off how can I tell by looking at front of cams on exhaust and intake side if timings off. (10psi of compression on all 6, blowback from intake end when cranking) I have the timing kit btw