Audi s2 3b won't start PLEASE HELP

[Stealthacq]

Hi I have an s2 3b that won't start
I bought it like this.
Am not one to ask for help but I ha e spent about 40hours on it now and really would seriously appreciate some help from the pro's
The diagnostic of my car so far:
#it runs on easy start
#fuel pump relay j17 powers up on crank and I have done a volume test and it dose pump the correct quantity
# there is power at the injectors
# there is a spark
# there is power at the coil
# I have ground all the injectors manually and they all operate
# it is all timed up
# it has new spark plugs
# I have cleaned all earths on the intake, under the drivers right hand well and passenger well
# the speed sensor has 4.2volts
# replaced the speed and crank sensor

have made a noid lamp and on ignition on I get a dim red light and when I start that's it.

Now to the pin outs:
The crank sensor does not have voltage on ignition on
Disconnected ecu and g4 and g28

I have continuity and installation resistance between each for speed sensor and crank to the pin outs and all is good

But no voltage to crank sensor at all

I won't give up but really need some help please

[Mikes2]

Are there any fault codes at all ?

The 3B workshop manual is here :

http://s2-audi.co.uk/workshop/3b_ignition/3bi.pdf

[Stealthacq]

Only fault code I get is the speed sensor but am guessing this is because it won't start.
I have been running threw the worktop manual and tested pinout to ecu on the g28 and g4 and all seems OK the only odd one I did find was the o2 sensor coax cable contact 1 to pin 28 was no continuity.
So I snipped and jumped across with a fly lead and still no joy

It's on page 28-14
Contact 1-28 no connection
Contact 2-49 ok
Contact 3-19 ok

[Dobby84]

Im sure you have checked this but are you getting fuel to the injectors?
Mine was doing similar to yours and one issue was that there was no fuel flow from the pump due to a broken wire from the relay to the pump.

[Stealthacq]

I have done the volume test taking the fuel rail off and in got 300ml in 3 seconds
And my noide lamp does not pulse when cranking.
Cheers for the response I really appreciate the help

[Mikes2]

Page 28-14 is for the crank sensor - not the o2.

So if I'm reading this correctly, you've got no continuity between pin 1 of G4 (black) to pin 28 on the ecu.

Is pin 1 shorting to any other wires ?

Where did you cut the wire ?

[Stealthacq]

I was wrong all the connections for the speed sensor and the crank sensor are connected correctly and I have insulation resistance tested them between each other.
Speed g28
Contact 1 Blue to pinout 48
Contact 2 gray to pinout 47
Contact 3 sheathed ground pinout 10

Crank sensor g4
Contact 1 red pinout 48
Contact 2 purple pinout 49
Contact 3 sheathed earth pinout 10

It was the o2 coax that has no connection to pinout 28

Am getting very confused now as on the Manual
28-14
Pin 1 contact of g4 goes to 28
But the wiring diagram says pin out 28 is the signal wire from the o2 sensor
The wire I cut was the coax o2 signal cable at the ecu but I have re connected it as I think I am wrong

This car did have a immobiliser at one pint but it's all been cut out. I do have a feeling it's something to do with this otherwise it could maybe be an ecu!!

[Mikes2]

No wonder you're getting confused - there's a typo in that 3B manual. It is pin 48.

Full list of pinouts is here

http://s2-audi.co.uk/tech_articles/motronic/ecu.htm

If you're not getting a pulse when cranking it, have you confirmed the flywheel pin is present to provide the signal.

I'd not expect a spark if it's missing but you never know

[twoqu]

Sounds like the injectors are not being grounded by the ecu. If you have VCDS/Vagcom you could try the output tests to verify that. If not double check the earth cables on the inlet or if the engine has been disturbed, the engine to chassis earths.

[Stealthacq]

I have the old snap on diagnostic kit
Al have a look see if that will operate the injectors
I have a small osiloscope on its way so I can check the sensors are all bang on time Av Herd that if it's out more than a mm it won't strike up.
And this will illuminate the key missing on the fly wheel
Are these hall sensors digital or analogue?
I got 12v from the injectors to the manifold.
I have cleaned all the earth's up drivers and passengers footwell.
The main earth battery strap to the chassis and the manifold
Let me know if there is any I have missed?
Is there anything I can do in the meantime as this osiloscope is coming from China haha
Cheers guys

[twoqu]

The fact it fires on easystart implies that its lacking fuel from the injectors
If you have spark and fuel at the rail then the ecu is happy. If you have 12V at the injectors then the only thing left is the injector triggering which is ground via the ecu. I guess the immo could have cut the earth from the ecu to the inlet manifold. Perhaps probe back to ecu pin 19 from the inlet manifold wire to check for continuity.

[Stealthacq]

Yes very true I will have a blast at that tonight!
Is the pinout 19 that brings on all the grounds for all the g4, g28 etc? Thanks

[twoqu]

I seem to recall that pin 19 is the major earth junction. I think that the others are all interconnected within the ecu. No harm in verifying them using the pin out.
As your noid is not flickering that also supports lack of earth.
Hard to be precise but hopefully you can see what I am getting at. Basically if the fuel pump relay is energised then the ecu is seing the engine being turned over. If you get a spark then the ecu is happy that the reference pin and hall sender are in sync. Does seem to point at the injectors. If you have power then it sort of points to the ecu triggering which is through ground.
There is an old fashioned way of doing the output tests through jumpering the 2X2 diagnostic connectors but its been so long that I can't remember how. It will be on here somewhere! That would at least prove or disprove the theory.

[Stealthacq]

Right checked pin 19 to the mani 0.05ohm I think that's a great connection.
I think k it's time to insulation resistance all grounds to 12v and signal cables.
Do I have to disconnect all electronic equipment or al fry it??
Al also try output tests Av prinked it off now
Cheers

[Stealthacq]

Update:
Sent ecu off to be Checked out today. Does anyone know if it has an immobiliser installed from factory?