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Discussion Starter · #1 ·
I am preparing to check the ti

I am preparing to check the timing on my BBi.

The OM states "Distributor static advance (at 5,000RPM)" to be 10 degrees. It then states "Advance at 5,000RPM" to be 29 degrees. I don't understand!!!!!!!

I have a timing light, and plan on running the engine at idle. According to a graph in the OM, the timing should be at about 5-6 degrees, at idle, not 10.

What marks, on the flywheel, should I be looking at........at idle, and at 5,000 RPM?
 
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Discussion Starter · #2 ·
OM may have a typo...

Timin


OM may have a typo...

Timing at idle 10-12 degrees BTDC,.. at 5000rpms 29-34,........ maximum advance is reached before 5K.....just rev it till max. mark is seen aligned with the pointer.

just before the PM 1/6 mark on the flywheel you should see the 10-12 mark.

painting the marks can provide easier viewing.
 
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Discussion Starter · #3 ·
JRV: Is the mechanical centri

JRV: Is the mechanical centrifugal advance mechanism being used, to set the timing at 10-12 degrees, at idle?

I know that the advance mech will advance the timing as RPMs increase, but is it working at idle?
 
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Discussion Starter · #4 ·
Idle is called static as the a

Idle is called static as the advance mech. should not be coming into play until more rpm's are introduced.
 
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Discussion Starter · #6 ·
Thanks Drew. I read the timin

Thanks Drew. I read the timing part, but my marks are different.

As I rotated the flywheel counter-clockwise (looking from the rear) with a screwdriver (worked well, JRV), I noticed the following marks, as I came upon them:

Note: I will use the "I" to denote a line going across the flywheel, so one does not confuse it with the number 1.

I A5 (has a green mark painted)

AA I

I AF (yellow)

I PM 1 6 (yellow)

I CS

AA I

I CS

I know that "I PM 1 6" is TDC. What about the rest? I am assuming the "AA I" and "I CS" refer to some form of cam timing.....right?



I
 
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Discussion Starter · #7 ·
I started the car, to see what

I started the car, to see what happens, with the timing. It seems that the timing is trying to "find itself".......not very consistent.....too hard to get a good reading. The idle is NOT steady.

The timing light is not giving out consistent signals.......seems to break-up.

When I accelerate, I loose the timing light signal if the acceleration is too fast........the light still breaks up at higher RPM.

Right about now.....if the dealer was closer, I would send the car to him!!!!!!!!!!!
 
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Discussion Starter · #8 ·
Henry, try putting the timing

Henry, try putting the timing light inductive pick-up on the coil wire, instead of the #1 plug wire. You should still see the timing mark but with 12 flashes instead of 1 it can give you some idea about the coil firing pattern and it takes possible issues with the cap & rotor out of the loop.

The dancing mark could be caused by irraditic spark or loose distrib flywieghts...not quite enough info yet to know for sure.

HTH's

Regards, JRV
 
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Discussion Starter · #9 ·
JRV: Just did what you stated

JRV: Just did what you stated.......interesting test to rule out the wires, cap and rotor! Many more flashes, but they DO still break up. This leads me to the problem being either the coil, or the Digiplex.........right?
 
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Discussion Starter · #10 ·
JRV: I just removed the coil.

JRV: I just removed the coil. It is a Marelli BAE 202 B unit. My references state that the primary winding should be 0.98 +/- 0.3 ohms. The secondary winding should be 6000 +/- 600 Ohms.

There are 3 terminals: One ground, going to the frame that holds the coil. One marked +B, and the other marked K.

I got a reading of 1 ohm between the +B and K terminals........I am assuming this is the primary.

Where do I measure the secondary reading from? I get a reading of 6,000 Ohms between the ground terminal and the center post.......is this the secondary?
 
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Discussion Starter · #11 ·
yes you checked the coil prope

yes you checked the coil properly. The problem isn't the coil....of that I'd bet money.

Was the timing at least close enough for Gov. work?
 
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Discussion Starter · #12 ·
I will go back and check.

W


I will go back and check.

While looking at the wiring diagram, I am assuming that either the Digiplex, or the magnetic impulse pick-up unit in the distributor, is causing the problem......now that I know it isn't the coil. Am I getting close?
 
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Discussion Starter · #14 ·
JRV: You are full of good news

JRV: You are full of good news....haha

Well I just came back after trying to read the timing.....unable to. The flywheel is very eratic, shifting back and forth. The paints are barely visible........just as I try to read the lettering, the flywheel shifts. I am lucky if it stays in one spot for more than 1 sec, before shifting. My eyes now hurt trying hard to read the thing. I think I will get some bright paint tomorrow, to better mark these.

I rotated the distributor, from end to end.....and the constant shifting of the flywheel still occurs.

How is it that you can rule out the pick-up......isn't it sending a signal to the Digiplex, which then regulates the coil?
 
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Discussion Starter · #15 ·
If the pick-up fails there is

If the pick-up fails there is no signal to the coil.


The fact that it even starts and runs pretty much rules out pick-up and coil.

Does the engine rev up? can you try revving the engine until the timing becomes more constant so you can get a feel for where it is set?

Failing setting timing with the engine running you can simply align the 10-12 AF mark to the pointer on cylinder # 1, turn on the key, pull #1 wire and hold 1/4 " from ground, and swivel the slightly loosened distrib back and forth till the circuit breaks, shooting a spark...

HTH's

Regards, jRV
 
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Discussion Starter · #16 ·
When revving the engine, the c

When revving the engine, the centrif. advance starts to take over, and the flywheel moves to another position, fluctuating a little less.

I will try your static timing suggestion. But I don't have the "10-12 AF" mark. I assume it could be the "I AF" mark......it is the closest mark counterclockwise to the "I PM 1 6" mark (looking from the back).

Can something loosen within the distributor which will cause the pick-up to "shake" around........even though it hasn't failed?

Is there a voltage signal that one can check, coming out of the ECU, to tell if it is working?
 
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Discussion Starter · #17 ·
I couldn't get a spark at

I couldn't get a spark at the "I AF" mark. Number 1 plug is right front plug, isn't it?

I removed the distr cap........lots of "green" spots......will order a new one, with rotor.
 
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