Non starting AAN

[slacky]

I don't think either of these sensor have any power. They produce a signal if you see what I mean.
They appear to be earthed via pin 19 which is one of the inlet manifold earths. So I would have a look at that closely, although you would have expected both to have been effected by an earth problem!

thanks

[newsh]

Would anyone be willing to test my ECU if I post it to them ?

Where are you based?

[quattro-nick]

you said on post 11 that g4 sensor gives nothing so that will be your problem
it's an inductive sensor so it make it's own ac voltage when the timing pin passes the sensor

[Error404]

Chris as suggested above try swapping the G4 & G28 over (they are the same sensor) and see if you get a signal - this will determine if the sensor or wiring is at fault. I find it highly unlikely the ECU is faulty.

[slacky]

you said on post 11 that g4 sensor gives nothing so that will be your problem
it's an inductive sensor so it make it's own ac voltage when the timing pin passes the sensor

True, that would make sense
Thanks

Chris as suggested above try swapping the G4 & G28 over (they are the same sensor) and see if you get a signal - this will determine if the sensor or wiring is at fault. I find it highly unlikely the ECU is faulty.

Yea thanks Alex , I'll swap them over at the weekend & report back

[slacky]

Where are you based?

Wirral up north'ish John

[slacky]

I don't think either of these sensor have any power. They produce a signal if you see what I mean.
They appear to be earthed via pin 19 which is one of the inlet manifold earths. So I would have a look at that closely, although you would have expected both to have been effected by an earth problem!

I'll look at this too thank you

[20Vcqdriver]

I always thought these sensors had 4v from the ECU to the sensor with the passing of the pin or flywheel teeth 'sinking' the signal as it passed. I found 4v at the centre of the plug for G28 that is giving a perfect sine wave as it should but no voltage at the G4 centre pin. The Hall sender is also giving a voltage on the centre pin as expected hence suspected either a wiring issue or ECU.
However, having just tested the plugs on my 3B it appears the sensor for G4 works by inducing a voltage spike. I have a working spare sensor here so will pass this to Chris to install and fingers crossed...

[slacky]

Oh joy it Starts ! 😜
Timing was out by 2 teeth .....

Question now is why did it jump 2 teeth??

20vcqdriver is thinking maybe the tensioner isn't tightened up properly??
So we're having a look at that tomorrow 😉

[newsh]

Non starting AAN

Did you check it using the flywheel zero mark?
It's possible the bottom pulley has moved

[Vorsprung durch Technik]

Oh joy it Starts ! 😜
Timing was out by 2 teeth .....

Question now is why did it jump 2 teeth??

20vcqdriver is thinking maybe the tensioner isn't tightened up properly??
So we're having a look at that tomorrow 😉

Glad your getting there Chris, good luck for tomorrow.

[UrS4boy]

Consolidated Cam and Crank Pulley and Flywheel Timing Mark photos and diagrams

Did you check it using the flywheel zero mark?
It's possible the bottom pulley has moved

Like this:

AAN Consolidated Cam and Crank Pulley and Flywheel Timing Mark photos and diagrams:

http://forums.quattroworld.com/s4s6/msgs/136943.phtml

[chezz]

Has the crank pulley keyway broken causing the belt movement?

[bernsaudi]

Mine was retarded by a couple of teeth when my bottom pulley key went. Also showed mechanical failure on the scanner.

[slacky]

Has the crank pulley keyway broken causing the belt movement?

Mine was retarded by a couple of teeth when my bottom pulley key went. Also showed mechanical failure on the scanner.

Yes a couple of other people have brought this to my attention too , which is still in the back of my mind/concern .....even though we've re- tightened the tensioner bolt (library pic from sjmautotecknik) -




After this we had a little drive & booted it a few times everything seems in order ....
I think ultimately the best cause of action would be cambelt change & crank sprocket inspection in the near future ...?


It is also worth noting that the cambelt did seem rather loose, on initial inspection, when we replaced the aux belt about a month prior to the non starting issue.....