BMW Repair: BMW 1990 320 i cuts out in hot weather, deg celcius, faulty sensor

Question
Hi Don

I have a 1990 BMW 320 i  (box shaped) model . I stay in South Africa . I have a problem with my car particularly in hot weather . After driving for about 20 minutes the car would cut-out as soon as i get to a traffic light /or reduce speed . I would battle to getthe car started again . It will only go for 5 meters and cut -out again . Only after waiting for  5 to 10 minutes , the car might go again . This also takes place when the car has been standing in the sun for a long time . It never happens during winter time . We are having a heat wave currently and the temperature was 36 deg Celcius when this happenend. The car is also not overheating ( gauge is at 10 to 12 position ) I replaced the viscous fan 10 months ago as this was defective and resulted in overheating whilst idling .Could this be a faulty sensor somewhere?

Regards

Hugo  

Answer
Have all the basic services been done?The car being as old as it is age is important to remember.Filters,cap/rotor and plugs and checking the relays(take them out clean the terminals and reinstall)Checking the body ground (making sure the braided cable is not green at all)