familyman 0 Report post Posted April 12, 2006 I have a workmate who has a 525 and dosen't use his car because it stops running when engine warms up. Any ideas ??? Quote Share this post Link to post Share on other sites
topless 13 Report post Posted April 12, 2006 Does it just stop or does it start misfiring and then stop? Quote Share this post Link to post Share on other sites
bumpstop325 0 Report post Posted April 12, 2006 or he cant start it when the engine is hot? Quote Share this post Link to post Share on other sites
familyman 0 Report post Posted April 12, 2006 Car goes great until it reaches a certain temperature and then it just dies and will not start until engine cools down. Engine runs fine, no coughing,spluttering etc, it just cuts out. Must be electric of some sort ??? Quote Share this post Link to post Share on other sites
topless 13 Report post Posted April 12, 2006 (edited) The way I would attempt to dagnose this is, when it dies, first check for spark at both the plugs and also from the coil. Spark can be lost via a faulty rotor/distributor cap. (I am assuming that the motor is not one with separate coils on each spark plug here). This is the easiest check to do first that doesn't need any special equipment. If there is spark, next check for fuel delivery. remove the incoming fuel line from the injector bar and put it clear of the engine area into a bottle or similar and plug the nipple from the injector bar. Take really special care here that fuel can't spray over the motor. Briefly crank over the motor and watch for fuel being pumped into the container. If there is fuel and spark, the next thing you will need to do is check fuel pressure but you will need a pressure gauge for this. If the pressure is ok, then check for injector signal. The easiest method here is to use a long screwdriver and put one end on the top of an injector and the other press to your ear. Get someone to swing the motor over and listen for a regular distinctive click. If this click is missing, it means the injectors are not getting their firing signal. If there is no injector click, you will then need to check that the crank sensor is functioning. You will need a multimeter for this. It will depend on what motor you have as to where it is positioned. If all this is ok, check the wiring carefully on the engine harness, paying particular attention to the earthing points. BMWs are notorious for having electrical faults if the earthing points (of which there are many) are faulty. These earth points can go high resistance when a certain temperature is reached as can other junction points etc. Once you have possibly eliminated all of these, the final call for me would be the ECU. Try to find someone with the same car, check that the ECU numbers are the same, and swap ECU's. If none of this works, we will arrange a photo session of us pushing it over a cliff.... I do have a full Bently manual for the 525 E34 so can assist further if you don't succeed.. Keep us informed. Will Edited April 12, 2006 by topless Quote Share this post Link to post Share on other sites
