3b s2 coupe resurrection

[andy10v]

Did you actually do the really basic check for fuel and spark?

Injector in a jar / plug laying on the cam cover?

No spark with plug on valve cover, I have not pulled the fuel rail out yet.

[andy10v]

Thanks Alex and twoqu, I will read the link properly after work, looks interesting.

Martin, Alex has lent me an ABY ECU and injectors, thanks for the offer though. If you are through a look over would be great as I have looked at it so many times I probably wont see something obvious.

I will pull the crank sensors out and see if I can manually test them?

[andy10v]

Maybe cam pulley has sheared?

The keyway so its out of time?

[newsh]

Any old injector would do, just plugged in.

[andy10v]

What will it do if its not in the fuel rail?

[newsh]

What will it do if its not in the fuel rail?

Hold it in your hand, you will feel it click

[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.

[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?

[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.

[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]

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.

[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.

[martinws]

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

[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

[newsh]

Any news Andy?