RE: E30 start problem - spark coil?

["Fadeev, Alex" <Alex.Fadeev@xxxxxxx>]

"Vlad" <vlad@domain.elided> asks:
> 
> My BMW is '84 318i with M10 engine. Three days ago I faced 
> with strange problem twenty minutes after stopping the warm
> engine it refused to start again - starter spinning, fuel 
> pump making short buzz (as usually) but engine doesn't start.

OK, we've got warm starting problems.

> I was staying uphill, so I slowed down backwards on 
> the level road. and then engine started normally. 

I was going to suggest fuel/air mixture problems (leaking injectors, coolant
temp sensors, spark plugs, etc), but if the engine started right up without
any problems this is beginning to sound like a spark delivery problem. 
Does the car die on you while running?

> Next day on the fifth minute after started cold engine when 
> shifted on third gear engine stopped without any luck starting
> it on the gear again while moving. Next day it gone even 
> worse - one trip without problem - one with stops after every
> five minutes, sometimes it wasn't possible to start it - 
> starter spinning, but engine didn't start.

OK, the car does quit on you randomly.
I don't have any first hand experience with M10 engines, but my M20 (B25)
had all sorts of weird cold/warm starting and random dying problems for 1/2
year until the DME finally died. May or may not be your problem. The worst
thing about flaky DMEs is that they are next to impossible to diagnose until
they finally quit. By then it is too late ;-) Spare DMEs go for around $250
in the US. No idea how much in Kiev.
Another possibility is a spark delivery problem. Double check everything:
the coil, the distributor, the plug wires and the spark plugs themselves. 

Basically, it takes 3 things for the engine to run: air, fuel and fire (a
spark). Make sure all 3 are present. Then make sure the DME is timing their
delivery appropriately.
My money is still on the DME going bad (if your car has one, that is).

> Also he noticed two things - it could be something to do with
> car alarm system milfunction (I have very basic Excalibur with
> shock sensor) 

Depending on how well the alarm was installed and how well it is working, it
is possible that either a butchered wiring job or a faulty alarm would cause
engine problems. Try removing the alarm to eliminate this possibility.

good luck,
alex f

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