QuestionI have a 1997 BMW 328i automatic. RPM sometime won't drop down when I stop at the light and won't down ship when the rpm is high. Sometime it is at normal rpm when I am at the light and certainly the rpm jump up to 2000 plus and the gear ship to the higher gear and the car want to move forward and the same thing happen when I am slowing down also if the rpm won't drop down to normal then it won't shift down to the proper gear and I have to use alot of break to keep the car stop. Can you help
AnswerHello Mr. T,
There is a problem in the way the EGS (transmission control module) and the DME(engine control module) are interacting with each other, perhaps due to something other than the two of them. I suggest that you bring it to an Autozone store or any place where you can have it scanned for fault codes.
Then, tell me what faults you have (all that comes out).
In addition, get data about fuel adaptation values (some call it long term/short term fuel trim) for both banks 1 and 2(first 3 cylinders and next 3 cylinders).
I can make a guess about your problem, but that is what it is, a guess. And I don't want to waste your time with guesswork. Regards,
Tino
PS
Here is my educated guess: you have a sticking throttle valve which can be due to gum deposits or dirt inside the throttle which prevents the valve from opening and closing
freely; or a mechanically wornout throttle valve wherein the valve snags; or a defective throttle cable that also snags.
Checking these items take some doing. You have to remove the
air filter housing, disconnect the airflow meter connector,and remove the rubber boots/big air hoses connecting the air filter to the throttle valve and the idle air valve(this is the hard part).
Clean the inside of the throttle valve with a clean cloth soaked in throttle or brake cleaner, check for free movement of the valve, replace valve if necessary.
There is a remote possibility that the problem can be due to other things, but this is the most logical one.
