Hi; Recnetly my 1997, 960 with 100,000 miles began running rough on occasion and after runing a while would shut down, will not restart cranks okay. After a few hours left alone it will restart and run again for a while. No check engine lamp on, fuel pump activates with key on, check spark plugs and coils seem to be okay. could not verify if spark was present or not. Timing belt good. Any idea what of how to check for the cause.

 

Pull codes. Then:

* Ensure fuel pressure is correct.
* Check for gasoline in oil.
* Ensure fuel injectors are not leaking.
* Check ignition and sensor wires for proper connection.
* Ensure spark plugs are not fouled.
* Check ignition and coil circuit.
* Check engine speed sensor.
* Check throttle switch and connector.
* Check idle valve. Ensure airflow arrow points in correct direction.

 

Besides the already mentioned items, the temp sensor could be at fault.

Next time it stalls and refuses to start, unplug the sensor, and try restarting.

The engine only requires two sensors to run, throttle position sensor and rpm sensor. All others can be missing and the computer has default settings to limp home. Of course you will then have a code to deal with.

But I am thinking fuel pump. Also see if you can detect a spark.

DanR '94 964 368,000 miles (134,000 on the new engine)