Agg mk3 won't start.....help

Right folks, sorry if this is a little long.... But it's doing my head in. I have just ended up owning a mk3 GTI (1997) fitted with an AGG engine.
The car turns over but will not start, I spoke to the previous owner a few months ago about an intermittent cutting out problem, sometimes starting straight away other times not doing. I suggested trying a crank angle sensor, however he was reluctant as it had had one a few years back (I suspect this to be a none gen unit)
The car has since been stood and the battery has gone flat, now charged, it won't start at all?
My code reader won't communicate with it, which at first made me think that the ecu was dead, but have since found it doesn't talk to my other mk3 or my 2002 caddy either. I have power at the ecu at pins 8, 23 and 38 and a good ground on pin 1 (eliminating the common relay 30 issue) there is no spark and no injector pulse (live but no earth). The fuel pump does prime.

Would a compatible code reader bring a code up for the crank sensor on a vehicle of this age?
Is there a way I can test the crank sensor?
If it were an immo fault would I get one cycle of spark and fuel?
Does anyone have any other suggestions?.

Thanks in advance

 

Check the wires going into the crank sensor, they crumble...

If the fuel pump doesn't run on cranking, 99% crank sensor problem.

Your code reader will probably only work on EOBD vehicles (2001> petrol and 2004> diesels) , and won't support old VWs.

VCDS may bring a crank sensor code, but would be able to show there is no rpm on cranking in the measuring blocks.

If immo fault, it would start then stop after a couple of seconds.

You should get an AC voltage out of the crank sensor with it disconnected (providing these use a VR signal type sensor)

Also make sure you have voltage on the red/black wire on the hall sensor on the distributor.

On the AGG the distributor is used as a cam sensor rather than the sole trigger for the spark.

I had this discussion with the AA guy when he told me that it was a distributor fault on my AGG when it conked out, his answer was

"Well I don't have a crank sensor on the van anyway , so we best tow you home" lol

 

Sounds like crank sensor to me.

My brother had the same thing on his AGG engine. The crank sensor was the last thing we changed, after messing about with leads, ect.

They tend to come loose sometimes too, so its worth a look

 

Thanks for the reply
I think your right about the code reader, it's a blue point microscan .The wires look it be good, the fuel pump primes with the ign, but not sure about on cranking, I'll check and come back with the info. Also i think ill order a cheepo vcds lead thing to run vcds lite. cheers for the info

 

Thanks Richard mk2 I think your right, if im honest Id just like to be sure before I buy one. Looks a swin to fit
Any opinions on non genuine ones, or is I best to stick with the real deal?

 

Yeah, those microscan things may be 'OBD2 compliant' but we (UK) didn't get OBD2 on mk3 Golfs, despite what the internet says sometimes...

If you're getting no inj. pulse and no fuel pump on crank it's more than likely to be a dead crank sensor.
Well worth getting VCDS, even lite with a cheapo K line cable for cars like this.

 

I'd personally stick with a genuine one, but they are costly. I think we bought a Topran one from Eurocarparts and it worked fine.

 

I used one from Eurocarparts IIRC, it worked and was about 1/2 price of genuine.

Needs the front engine mount bracket removing to fit.

Support g'box as starter bolts go through the bracket.

 

But would the crank sensor be responsible for not having a spark, isn't that controlled from the hall sensor in the dizzy??

 

On an AGG the crank sensor and hall sender in the distributor work in conjunction.

Distributor hall sender is basically the cam sensor.

Once running you can disconnect the hall sensor on an AGG and it will keep running IIRC!

 

Right, that would make sence, I read that it's one pulse per cycle on an Agg dizzy, as opposed to 4 per cycle on a PB for instance, which has no crank sensor.

 

Would this be the right lead to work with vcds lite
eBay item number 121392926902
Thanks

 

Yep. K line cable will work on anything up to and including mk4 Golf era of car, it won't do mk5 and newer stuff that uses CAN for diagnostics.

http://www.ebay.co.uk/itm/121392926...l?_sacat=0&_from=R40&_nkw=121392926902&_rdc=1

When you download vcds - lite from Ross-Tech make sure you download the file for 3rd party interfaces.

 

Cheers fellas, ordered one, I'll price the sensor options tomorrow and get one ordered. I'll post my results later in the week when I've had some tinkering time.
Thanks for the help

 

Cheers for the help, on returning to the car, it started when I fiddled with the wire on the crank sensor, it died, I repeated this a few times to make sure. I then replaced the sensor. It's been fine since I got a sensor from euro for 29.40 inc vat.
I later confirmed the sensor with my cheepo vag com lead so all it would appear is now fine,........apart from the abs fault and the air con not working

 

That's great, glad you got it sorted

 

Always good when people reply back when they have fixed a fault.

 

Richard mk2 - cheers pal, I'm glad I sorted it too, looking forward to getting on the road.

GVK - it's only manners to say thanks, plus.... There is nothing worse than reading a thread with no conclusion

Cheers everyone

 

Too right!

Might help others searching for info in future too.