I was normally drivign with my volvo and sudeenly it died. After trying to find oit whats wrong i found out that my rotor was broken so i bought a new one. When i got the new rotor istalled mu car started normally and was running fine but then after few kilometers it broke again. I have replaced it now four times and it keeps breaking and I don't know what is wrong.

 

How about either it's not installed properly (pushed down all the way), the cap is on crooked, or perhaps the bushings are worn out in the distributor base allowing the shaft to spin "out of round" and the rotor contacts the poles in the cap, breaking it.

 

I bought new distributor and it still does it and I have checkd that the rotor is pushed all the way down.

 

When you say it is breaking, how is it breaking? Are the electrical contacts breaking? Is the body of the rotor physically breaking off? Is the locating tab where it aligns with the metal distributor shaft breaking??

 

It is the locating tab on the rotor

 

The only thing I can think of that would cause the locating tab to break is that the rotor is binding while the metal shaft is spinning. The only way I could see that the rotor would bind is if it is somehow binding against the cap, or the rotor is getting jammed between the poles on the cap. Have you replaced the cap recently?

 

I have changed the cap week ago and it still does that

 

The rotor must be hitting something:
Are there any marks on the inside of the cap?
Are any of the contacts in the cap or on the rotor loose or become loose?
Is it possible the spark advance mechanism is causing some kind of misalignment?
Does the engine ever back fire or pop?
Can you make it happen by just cranking the engine?
Is the cap and rotor the same for all 740 engines?
What year car, model and engine is it?

 

the rotor isnt lose or anything but it might hit the cap and it doesnt backfire and I think it is the same cap in any 740 engines. I have b230f year 1992 745