525i dies when hot??

[John B.]

A friend of mine is trying to fix an odd problem with a 1995 525i. The car starts just fine & idles/runs fine for about 15 minutes then it just stops running as if someone had turned off the key. No odd idle or stumbling before it dies. After it sits for about 30 minutes it starts right up again but up until that time it just cranks over. So far the owner has replaced the fuel pump, f/p relay, fuel filter & swapped in a different Mass Air Flow Sensor. Nothing changed. Any ideas?

[shogun]

did you check the fusable link for haircracks ? Once we had a problem with an E31 850, that has 2 fusable links. Sometimes it worked like a charm, when switched on and parked, after coming back the owner could not start it. Other times it started. His wife - which drives the car mostly - already asked him to sell the car as she did not trust it anymore. So after 6 months of trying he asked our DIY team and we found that one of the 80A fusable links hidden in the battery cable in shrink plastic had a hair crack, replaced that and no more problem.
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Before he also changed the ignition switch, as this also sometimes causes trouble, but that was waste of money in this case.
Item #3 Steering lock/ignition switch BMW 5' E34, 525i (M50) (http://bmwfans.info/parts/catalog/E34/Sedan/USA/525i-M50/LHD/A/1995/may/browse/steering/steering_lock_ignition_switch/)

[Bill R.]

7814 I would suspect the dme relay or as bmw calls it here the engine control module relay 6300, you can pry the cover off of the relay and solder up the joints where the relay joints the circuit board, it will have small circular cracks on the circuit board where the relay is attached, usually at least 4 points to resolder.

[Tiger]

Crank Position Sensor.

[John B.]

I passed the tips on to my friend. I'll let you know what he finds. Are the symptoms typical of a crank sensor failure?