Distributor bolt access

I have an '84 400i with the single distributor. How can I access the three bolts to adjust the timing? The one is obviously easy from the right side of the engine bay. How about the other two? What type wrench and how to reach them.

I appear to be in bad need of a timing adjustment. I think a DPO used the 30 degree mark as if it was 0! I first thought I was one or two degrees off at first but the TDC marking did not look right. So I rotated the flywheel to find a 30 degree, an 8 degree and a "PM | 1/6" mark as it is supposed to be. I made a nice white line on the TDC mark and went back and rechecked to see that I have 35 degrees of advance at 1000 RPM. First thing I did was to recheck that I was on #1 cylinder and I was.

I am probably lucky I have not burned a piston! I have been reading posts about some people thinking their recently purchased 400 was a little sluggish and I was beginning to feel the same. I expect a substantial improvement in performance if I get this right. So help please with my questions.
Ken

 

I bought a cheap set of wrenches and bent a 13mm box to around 45 degrees.

Also, you might want to pull the cap and look inside. Water can collect and muck up the advance weights, locking the timing.

My biggest performance improvement came from cleaning the injectors. I've been using Amsoil P.I. in every third tank of gas and each time I see an improvement. When I get a chance, I'll pull them and do a hand pump cleaning.

 

If you really have 35 degrees advance at 1000 rpm, I'm surprised it will run.

As Mark eluded to, you could have an advance problem.

 

Mark and Tim

I managed to get to all of the bolts by sitting on the left fender with a suitable cover on it. I actually went through two cycles of loosening and tightening and so I got reasonably good at it. My son has a set of open ends with one end at 90 degrees to the shank but unfortunately the 13 mm was missing; it would have been perfect.

Now for the timing. Apparently my timing light does not like 12 cylinder motors; it appears to take double the knob adjustment than actual to get the light on TDC. After figuring this I decided to keep the adjuster on zero and use the flywheel marks. I found that there are really two sets of marks on the flywheel a relic of the two distributor motors. There is one set for cylinder 1/6 and another for 7/12. There are marks for 8 degress BTDC and 30 degrees. So I added a little paint line to each of the three marks (also TDC).

I was able to get perfect timing settings of 8 degrees at idle and exactly 30 degrees at 5000 RPM. It sure was fun laying 18" below the car with that roar above you!! I was surprised that at 3000 RPM there was still 5-10 degrees more advance to go. But as soon as it got to 5000 RPM there was 30 degrees.

After all of the fiddling, I figure that the motor was advanced about 22 degrees too much. Yes, it ran but it did not like to rev like it should. Actually most cars idle better and faster with too much advance. The good news was taking it out and driving it. Throttle response is greatly improved and it sure does like to REV! I think I now own a Ferrari! My next (third) "road trip" should be a little more exciting and I wonder how it will affect the mileage, I have been getting on the plus side of 14.

I continue to convert this car from someone else's Ferrari to my car. I am taking my time and getting one thing right at a time. Next week will be the CO test / adjustment.

Thanks guys.
Ken

 

Good Job!

Glad you had a postive outcome.


That missing wrench (13mm angle pattern) is one of the handiest tools for working on these cars.

A powerful small flashlight, a good inspection mirror and a selection of magnetic pickup tools come in really handy as well.