intermitent stalling on e34 535i......

[twoplusone]

Feels like a failing fuel pump or ECU. Could possibly be a fuel pump relay, main relay or 02 sensor relay. Was wondering if anyone else had any input or similar problem.

[Derek A.]

symptoms? conditions ? ecu codes? basic diagnosis (fuel pressure, spark)

[Martin in Bellevue]

The crank position sensor can give hell to the ignition system. Bentley has resistane values, that can be measured at the socket, or even back to the big harness socket to the DME. I experienced a crushed wire under the black plastic harness box over the injectors; no fun.

[gale]

Does it re-start easily right away after it stalls? If so, then I'd rule out the ECU as the culprit although it could be one of the relays as you mentioned. The ECU temp sensor (the blue one on the thermostat housing nearest the head) can cause the mixture to lean out to the point of stalling at idle. The temp sensor shoud measure on the order of 2 k-ohms cold and between 270-400 ohms when warm. If it measures below 200 ohms when warm then that could cause stalling issues but only at idle. If it's stalling at higher rpms then I don't think the sensor is the problem.