BMW Repair: 1987 745i euro w/fed, air flow meter, chassis number

Question
QUESTION: Hello Tony,I am one of the other BMW tech here on allexperts.I see that in your profile it says U.K.I am in hopes you have had the European experience that I need to know for this car.It is a 1987 745i (turbo) with US Federal specs.The problem is it is considered a grey market car and specs and information is difficult to get.Wiring diagrams here are for US spec cars and nobody knows anything about theses years cars.Which I work on but euro cars do differ. My problem is it starts runs the 8 sec cold start,but unable to throttle up.I would like to know what I might be able to check in the air flow meter or would you have an idea what it might be.I work on these cars all the time,have my own shop and do have most tools required for anything.I need some help here and being able to get a hold of a European wiring diagram of this car would be so nice. Thanks good luck

ANSWER: Hello Don, I knew eventually someone would come up with a question about a 745!

I have only seen 2 and that was when i lived and worked in California for 30 years, so i am afraid we are in the same boat.

Been here 25 years and never seen 1.

I would suggest asking on a few forums, asking someone doing what you are doing in another state(they might have a copy of a wiring diagram and send you the info)

Other than that feel free to give me more info such as chassis number and clarify(translate) what you mean by wont throttle up?

Do you mean it starts on the cold start and then stalls?

Put a noid light on the injectors to see if they are firing,if not check the distributor(if it has 1) There should be a couple of "points" inside the distributor, they control the fuel injection, and as i recall they are accessible from the sides of it.

It could be getting enough fuel to try and start from the cold start(totally separate) with the other injectors not firing.

Feel free to send me more on this 1, will get the cobwebs out of the way

Tony

---------- FOLLOW-UP ----------

QUESTION: It does start but then stalls.If you feather the gas pedal it will stay running but not enough to drive.I did have it running one time the weather was hot and humid.After that it was back to the same issue as before.It is Motronic so there is no distributor.

Answer
Have a look at the reference "pin" on the flywheel,I have seen them break off on a few motronic systems and the reference sensor see's only whats left sticking out,usually the weld.

Its the one further back, the one in front is the rpm sensor reading the flywheel teeth.Move the flywheel until the pin is visible through the hole from the removed sensor.

Both sensors generate an a/c voltage and can be checked with an ohm meter, an analog one would allow you to see the "spike" of the reference signal.

You could test the afm with the same meter to see if the resistance changes in a linear scale when you open the door, but I also like to remove the black cover, and clean the carbon plate with brake cleaner.

I take it the plugs are not black indicating too high fuel pressure.
The correct fuel pressure should be stamped on the regulator itself.

If you can get it running while the cover is off of the air flow meter,move the arm clockwise a little to see if it revs.That would indicate the afm is faulty,

You can adjust these, but paint a reference mark on it first!
Lift the locking spring while holding the wheel(its spring loaded and will want to jump) and move it a couple of teeth either way.

remove the distributor cap, throw away the plastic cover and have a good look for arcing especially where the cover was on the outside!

I used to crank them over IN THE DARK to watch the arcing.Be sure to look at the rotor arm carefully for burn marks especially if its the old rpm limiter type. something like 1k ohms max

My brain hurts, cant think of anything else to offer but please let me know your progress.

Tony