Question have a 1991 525i E34 from time to time the engine stumbles normally when i have been waiting at traffic lights, if i dont blip the throttle before setting of the car will stall.
Sometimes i can be on the motorway with the throttle at a set postition when i put my foot down the car doesn't accelerate, i can be driving at a steady 30 mph i put my foot on the accelerator and the will stumble.
Can you please help
AnswerHi there.
Okay, where do we start? There are many reasons why a car would do this and the best advice I could give would be to have a diagnostic test done by dedicated equipment. This usually ends up being cheaper that trying to sort the problem out by a process of elimination.
However, that's not what you wanted to hear!
Try the following...
Check for vacuum and air leaks, in particular the rubber hose near the MAF (you can do this by spraying a very FINE MIST of water or WD40 over the area, if there is a leak the system will induct the mix and stall). Also, if you have a cat fitted you might want to check that to make sure that the thing works. This can be done with a multi-meter, check for any resistance between the wires (don't worry about which colour they are but one will show a resistance of between 1-15ohms).
But these are the other potential culprits...
Fuel filter; fuel pressure regulator; injectors; Throttle position sensor; MAF (mass airflow meter).
Try the first lot and let me know how you get on.
Good luck!
Regards
Rob
