3b s2 coupe resurrection

[sidrick]

Seems rather drastic, though I certainly appreciate the frustration you must be experiencing.

If you're at a dead end then buy some beers, buy some burgers and organise a BBQ meet where a few of you can brainstorm If nothing comes from that, you've still got the matches from the BBQ......

[twoqu]

Have you got a decent crank pulley to swop out? At least that should give you correct basic timing!

[andy10v]

Still no start.

I am done, let the vultures descend.

[andy10v]

No advantage, I bought the billet pulley as it should be direct fit, can be resused multiple times, and should not fail like an OEM one can, it seemed like cheap insurance. The crank to cam timing has not been touched in any way since it was running, the 1/2 tooth will have shifted the power band slightly, as you would with an adjustable cam gear.

I will fit the dizzy and cam sensors when I get a chance, see if it starts. If not its on borrowed time.

[twoqu]

Flywheel 0 results in cam timing being 1/2 tooth out, as it has always been since the new billet pulley was fitted, and the car has been running like this, having a look about a few people have had the same issue with the tommis billet pulley, the keyway is not in the exact place it should be, so I appear to have the same issue

Frankly if this is the case then perhaps its worth a revisit! What advantage is there in being half a tooth out. Just has a knock on effect where you basically have no basic timing marks to reference!

[andy10v]

Not touched it.

Got a good dizzy and crank sensors to try, just need time to fit them.

[newsh]

Any news Andy?

[andy10v]

They are the same as far as I know. Thanks for the offer but I have a pair and a dizzy on the way.

cheers

[martinws]

Are crank sensors the same as ABY? if so, you can borrow mine.

[andy10v]

Flywheel 0 results in cam timing being 1/2 tooth out, as it has always been since the new billet pulley was fitted, and the car has been running like this, having a look about a few people have had the same issue with the tommis billet pulley, the keyway is not in the exact place it should be, so I appear to have the same issue

That will not stop the car from running, as it was before, just the mechanical cam timing is not optimised. Should the dizzy then be 1/2 tooth equivalent out? Or just the dizzy marks in line when the crank mark in line? (that is how it was running before).

Spent some time with my dad messing about today, flywheel tooth sensor is ok, plenty of fuel out the fuel lines when cranking!

No spark, no fuel. No click from a spare injector. Previous wet plugs must have been false from output tests as suggested.

Dizzy timing has been tried in variety of possitions advance and retard with no change.

So flywheel timing pin sensor or hall sensor?

I guess I can swap the crank timing sensor onto the flywheel rpm to check it activates the fuel pump to confirm its working?

Going to try and get a dizzy and crank sensors anyway.

[twoqu]

Also if you look at those traces on that link it appears that the TDC signal should appear when the hall sensor ouput drops, which presumably is when the window appears. We know the pin assignments are reversed from 3B to ABY but surely the function is the same.

[newsh]

Just read the Picoauto link twoqu put up.

Well we all know that you can't rely on the front pulley mark to time a 3B and that the bottom pulley is often broken by people using the wrong tools when tightening, well worth checking ALL the timing marks again mate. Paul S2Central did a post a while back where he showed Hall and TDC traces overlaid, it should indeed look like this.

[twoqu]

If we rule out the bottom pulley then the only thing left is the cam pulley!
Car seems to have history of mechanical timing mark misalignment. If the hall sensor and timing pin are out of sync and there appears to be a window of sync it needs to be in, then no spark.

[andy10v]

Just for clarity the ABY Motronic Manual shows the following:
Pin 1 goes to Pin 12 in ecu which is the 5V reference out.
Pin 2 goes to Pin 8 in ecu which is signal back in.
Pin 3 goes to Pin 19 in ecu which is the ground.
There is supposed to be 4.5-5.5V between Pin 1 & 3.
There is supposed to be 4.3-5.2V between Pin 2 & 3.
So its only Pin 2 that should change when the window is opened or closed.
As Error as said it appears that the pin assignmemnts were reversed from the 3B!
However we know that the engine started so it seems likely that the wiring was correct.
I remembered this:

http://www.picoauto.com/tutorials/audi.html

Unfortunately most of us don't have a few £K to drop on this piece of kit. But if you read carefully it says the engine would start sometimes when letting go of the ign key and even when it started it basically would run for 5mins before dying again. So that seems consistant with your issues. It also ties in with that hall sensor out of sync code you had.
So perhaps its a mechanical rather than electrical issue.

So re assemble and check timing again, possibly try a dizzy a baw hair each way incrementally and see.

Could be the dizzy has moved, and play in it was allowing it to fire once as the starter was let go and it slopped the other way?

[andy10v]

Perfect, thank you, I was thinking I would not hear it click with the engine spinning.

I popped the crank sensors off, look undamaged, ends are magnetic.