How to align dizzy - couple of questions

[Jonas_R]

Reading through different threads on here how to align the dizzy and I think I'm getting more and more confused.

Why is it important that the engine is turned to TDC?

Is it possible just to make some marks on the dizzy before I take it out and then reuse these marks?

Can anybody explain the relations between the hall sensor, metal gear and rotorarm?

Or perhaps post a link to a thread that explains it really well.

[4WheelDrifter]

It's best to turn the engine to TDC so that you can be sure the distributor is timed correctly in relation to the cams and crank, so that the ignition spark goes to the correct cylinder at the correct time.
I'm not sure how accurate you can make your own marks. Why not use the marks that are already there?



You can see the 'window' in the disc below the rotor arm that triggers the hall sender, in the same way that it does on the cam pulley on the ABY/ADU. The sender itself is between the two marks.

The metal gear is used on replacement distributors, as the original plastic ones tend to break up over time.

[Flat on my back]

Oh god...

are you sat down...right, i'll begin...it all started when...no...different story

Answer is basically the ecu needs to know when the engine is at tdc (intake) to coordinate the firing and injection cycle.

So, we have a sensor in the dizzy and a sensor on the flywheel...when the 2 match up that is TDC (intake) piston 1 and we're all for go. If not yur engine dont start...btdt syndrome.

Remember 2 crank rotations is 1 four stroke cycle.

Best way to do things is...

Plugs out, dizzy cap off, turn engine over by hand until piston 1 is at TDC, check with long screwdriver in plug 1 hole...rotor arm MUST point to plug 1 connection at the dizzy cap.

If not rotate engine to next TDC on piston 1 and this should match up...make a mark the head and dizzy so they can be installed 'inline' when you pull the whole dizzy out.

Jesh, this is hurting...you got a phone no.?

[Knight Rider S4]

Did I not send this to you ?

If all these are in place as pictured you will have no problem

[Flat on my back]

.

Ddu know how long it took me to type that...i'm orf...

Nice piccies.

[4WheelDrifter]

Nice clear pictures Steve. Much better than my dirty, rusty old banger.

[Knight Rider S4]

Yeah before I started on the 3B I went on the hunt for all engine info I could find and saving all pics of timing so on ..these came from American Audi 200 website ..somebody had allot of spare time as you could see

[Jonas_R]

Steve: Don't think I got the first picture with the dizzy markings, but the rest I got.

Thanks for the info will turn the damn thing to TDC and use the screwdriver trick and give it a go when I get the inlet manifold of.

The outer housing that has one of the two timing marks. Does it bolt into a specific position on the block or can it be rotated as well?

[Knight Rider S4]

Are you taking the timing belt off?...and what you actually doing?...no need to do the screwdriver thing just take off the timing belt cover turn engine over by had till the marks line up as illistrated in the pictures i posted ..

[Jonas_R]

I'm taking the dizzy out to replace the plastic gear and the hall sensor element.

[4WheelDrifter]

When you put the distributor back in, first make sure the rotor arm is pointing in roughly the same place as it was before. Then rotate the outer housing so that the two marks line up exactly, with the engine at TDC of course.

[urquattro-island]

you

Steve: Don't think I got the first picture with the dizzy markings, but the rest I got.

Thanks for the info will turn the damn thing to TDC and use the screwdriver trick and give it a go when I get the inlet manifold of.

The outer housing that has one of the two timing marks. Does it bolt into a specific position on the block or can it be rotated as well?

rotate the outer of the dizzy, the inner is turned by camshaft.

[Jonas_R]

Is the inner part fixed or can it be placed in different ways?

[4WheelDrifter]

The inner part can be placed anywhere, within reason. As long as it is driven by the camshaft. But the two marks must line up at TDC.

[Flat on my back]

Jesh...

Right...like this...

1.plugs out, dizzy cap off,

2.turn engine over by hand to tdc, does the rotor arm point to plug 1 at the dizzy cap.

3.if not turn engine over to next tdc...ditto.

Now...mark on the head and base of dizzy with a line or punch 2 small dots, one on each.

Remove dizzy...fit metal gear.

When you install the dizzy the rotor arm will rotate because of the gear wheels...just make sure the 'line or punch marks' go together and the arm points to plug 1...the first time it goes in you will see the arm rotate and all will become clear.

HTH.