Hi Aslan,

Is that the B230K engine?

Are you losing spark when it wont start
or perhaps the coil is not seeing full battery volts when cranking?
put a meter on the coil see if you get battery volts
maybe you have a flakey ignition switch.

There's more stuff peculiar to the B230K
There's an idle compensation relay and a hot-spot relay
Do they have the hot spot PTC resistor at the intake manifold inlet
in the tropics?

The idle compensation relay looks like it just works while cranking
to send +12V to pin 9 of the EZ-K control unit
the two relays are mounted on the drivers side post near the power steering
fluid container

The relays have different pinouts:
the idle compensation relay: coil-pins 85 & 86 contacts- 30 & 87a
The "hot spot relay" which is mounted furthest away from the engine
the coil is 85 & 86 and the contacts are 30 & 87
I'd be careful not to assume that relays are interchangeable.

The hot spot PTC resistor is mounted at the intake manifold and
the control thermostat is next to it with one black wire to the relay and
a second black wire to an intake manifold ground "E"

Do you see a good spark when the engine wont start?
what do the plugs look like when it wont start and after its running

It's just a hunch to check for +12v at the coil when cranking
maybe there's a flakey ignition switch that sometimes resistive?

Its also a good idea to service all the grounds especially at the intake manifold, frame to battery etc.

I hope this helps you, Bill