s2 aby will not start (vagcom only show g28 speed sensor fault)

[EvenM]

copper doesn't last as long as these

Okey, thanks again

[newsh]

Will change the spark plugs But I dont think they are the problem. I can give full throttle but not for long, after reaching 3-4k rpm, it cut the ignition or fuel. It cant hold max boost for longer than 2-3 seconds before it cut the power.

After it cut the power the first time it starts to cut the power right away the turbo begins to spools up. I can turn the ignition off and start the car and I can give full throotle again before it cut again after holding boost for 2-3 seconds.

Boost leak or MAF connector.

Read this

http://www.s2forum.com/forum/showthread.php?t=24544

[EvenM]

Update: the story goes on...

Yesterday it didn't start again, now it get fuel when turning over, the sparks were wet, but no spark, so will check the g40 and maybe g4 tomorrow. I have ordered ngk plugs, waiting for them to arrive

[UrS4boy]

Update: the story goes on... Yesterday it didn't start again, now it get fuel when turning over, the sparks were wet, but no spark, so will check the g40 and maybe g4 tomorrow. I have ordered ngk plugs, waiting for them to arrive

Hmm....

*IF* the fuel injectors are firing and spraying fuel into the engine, that means that the ECU is happy with the signals from the G4, G28 and G40. If there is no spark, at this point, all I can think of is the fuse for the coils is fried.

Check the fuses under the "Motor" cover, fuses 27 and 28 (assuming this is an ABY S2):

[EvenM]

Hmm....

*IF* the fuel injectors are firing and spraying fuel into the engine, that means that the ECU is happy with the signals from the G4, G28 and G40. If there is no spark, at this point, all I can think of is the fuse for the coils is fried.

Check the fuses under the "Motor" cover, fuses 27 and 28 (assuming this is an ABY S2):

Thanks, didn't think about that the ecu need signal from all the sensors to even start the fuel pump

It was - 20 degrees outside yesterday, so I was quick and just checked the spark plugs, and they were soaked, so I'm positive that it was pumping fuel into the engine, but no sign of firing But will check the fuel rail to be sure

Will check the fuses tomorrow, yes its a aby

As always, your help is deeply appreciated

[EvenM]

Boost leak or MAF connector.

Read this

http://www.s2forum.com/forum/showthread.php?t=24544

I see I forgot to reply, but thank you very much, will check the connector

[220bhp]

My vote is the same as Newsh. Maf connector. I had the same problem cured by using a pair of needle nose pliers. I used an old maf I had and just gave the male connectors a little twist. not much, just enough to make a difference. and boy what a difference, haven't had a problem since.
I have also done the same to my newer maf, and its working to.
Cheap fix if it works. Nothing lost if it doesn't. Good luck.

[mullder]

copper doesn't last as long as these

I think you will find all NGK plugs are copper.It is what they use for the centre electrode and NOT the tip ( Firing end in the combustion chamber ) as obviously copper could not withstand combustion temperatures. The reason that palladium or iridium is used is because of their abilities to withstand very high temperatures and have excellent conductive qualities and good resistance to spark erosion It can be used to create a smaller diameter centre electrode at the firing end of the plug increasing the intensity of the spark over the standard size of the electrode on standard spark plugs. works on the same principle as sticking finger over the end of a garden hose . Decrease the diameter of the hole and see how much stronger the jet of water goes .Simples !

[EvenM]

Thanks for all the information guys

Started today with fitting a recharged battery and it fired right up. Either its a bad connection somewhere that come and go, or it just needs a very good battery to turn around fast enough for the ECU to send signals to start? Weird.

[UrS4boy]

J17 Fuel Pump Relay info

Thanks, didn't think about that the ecu need signal from all the sensors to even start the fuel pump

Started today with fitting a recharged battery and it fired right up. Either its a bad connection somewhere that come and go, or it just needs a very good battery to turn around fast enough for the ECU to send signals to start? Weird.

Not weird. The ECU needs to see a G28 signal that indicates the engine is spinning at more than 13 RPM before it will energize the J17 Fuel Pump relay by taking it to ground via pin T55/3. The J17 does more than just power the fuel pump.

J17 Fuel Pump Relay info:
http://forums.quattroworld.com/s4s6/msgs/22583.phtml

[EvenM]

Update: Changing plugs from Bosch to NGK seems to have solved the engine 'cut' problem as you guys said, thumbs up, so happy The car is getting closer and closer to be ready for new mapping with the rs2 setup