Wiring Masters Needed B3 90q with AAN swap

[UrS4boy]

Yeah they were pretty dry. What is wrong with the wiring still? The LED light test worked. I am not getting spark for some reason either but I am getting switched power at pin 27.

FYI: its not the POS sensors because I have the high output kit from 034

So now you have to establish the following:

1. that you have power to the coils with the ignition turned to "on", white harness connectors in an AAN. You need a multi-meter set to DC Volts to do this.

2. that you have spark during cranking (starter activated). This DIY should help:

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

If you have spark, button things up and move to (3)

3. that you have fuel at the fuel rail while the starter is engaged. Probably easiest to pull the injectors and fuel rail out of intake manifold as a unit, placing a glass jar under each of the five injectors and having somebody turn the ignition to start and see if anything comes out. I suspect not.

[Durr McDanks]

Yeah they were pretty dry. What is wrong with the wiring still? The LED light test worked. I am not getting spark for some reason either but I am getting switched power at pin 27.

FYI: its not the POS sensors because I have the high output kit from 034

[UrS4boy]

hmmm it didnt fire and I am pretty sure its timed properly too... maybe I fouled the spark plugs

Pull them and check/dry them. I have the feeling that they are dry and you still just don't have the wiring quite right. But hey I will be pleased to be proved wrong.

[Durr McDanks]

hmmm it didnt fire and I am pretty sure its timed properly too... maybe I fouled the spark plugs

[S2central.net]

Dont worry about it for now...

[Durr McDanks]

Ok will do! I have a question how important is the charcoal canister for the N80 Evaporative Emissions Control Valve? I didnt receive a charcoal canister when I bought my engine.

[S2central.net]

@Durr - crank it and see !

@Dave - you are correct about the maf afterburn pin which is what also confused me at first. It would seem the maf needs to be powered up via ecu#37 for the afterburner to work.

I feel an animated drawing coming on (ooer missus)

[Durr McDanks]

I just did the LED test and sucess it does only light when cranking but it only stays on for 2 seconds or so after turning off. Also, I found a wire that was giving 10v to the cam sensor and snipped and now thats no longer a problem. If I got that LED to light does that mean I am close to turning over?

[UrS4boy]

Paul: I know that the ECU sends 12v through the MAF wires on shut down but I understood that that was done via pin 25/55.

http://forums.quattroworld.com/s4s6/msgs/21009.phtml

I know you are busy and I do want you to get to the bottom of this 87A/Pin 37 thing BUT...I just sent you a PM with links to a very interesting early AAN cam sensor wiring "issue". I'll look for your PM when you get the time.

[Durr McDanks]

Ok, I will check it out with an LED test. Also, I havent touch my hall sender wiring at all so I have no idea why it would be getting 10v?

Urs4boy I for sure have my fuel injectors hooked up to 87a.
B3 90q fusebox-->87a-->splits to two wires-->wire 1 goes to unprotected side of S75
-->wire 2 goes to unprotected side of S116 *(S116 injector fuse in my case)

Also, in my case of the AAN/ b3 90q the fuel pump is labeled as 87f. I dont know if that matters.

[S2central.net]

This is why I knew something hurt my head when I did the fuel pump relay mod with the internal led. Look carefully at schematic for the FP relay - pins 87 and 87a are physically separate - they are only common when the relay is energised by the ecu. 87 goes only to the fuel pump. This means that the ecu can light up 87a via pin 37 when it is powered up.

I only discovered this when I wired up the FP led to terminal 87a and BS- do this on your aan to see if behaves the same - including holding it at 12V after shutdown for a few seconds.

Posting from a train here so aplogies if not crystal clear !

[UrS4boy]

@Durr - your post just reminded me of something from when I looked at this on my own car (aby). I think it is correct that pin 37 is 12V when the key is on - this powers up the MAF and gets 12V to one side of the injectors nice and stable before cranking over. At which point the FP relay energises and gives a 2nd source of 12V to injectors etc - shares the electrical load and avoids overloading the ecu internal relay. The ecu holds pin 37 after shutdown as described before. I can test at weekend to be 100% sure.

Okay that goes against everything I know. What you are saying is there are two 12v pathways to the injectors and one of them is through pin 37 whereas the other is through pin 87A on the FP relay? Don't two voltage pathways to the same point, one unfused, one fused go against good wiring principles. This would be back feeding to the FP relay.

Making my head hurt here Paul.

[S2central.net]

@Durr - your post just reminded me of something from when I looked at this on my own car (aby). I think it is correct that pin 37 is 12V when the key is on - this powers up the MAF and gets 12V to one side of the injectors nice and stable before cranking over. At which point the FP relay energises and gives a 2nd source of 12V to injectors etc - shares the electrical load and avoids overloading the ecu internal relay. The ecu holds pin 37 after shutdown as described before. I can test at weekend to be 100% sure.

There seems to be something wrong with your Hall wiring though.

[UrS4boy]

Any thoughts? Well yes. Like you do not have the fuel injectors wired to a relay that is only energized when the ECU approves of the conditions, i.e. the G40 cam position sender and the G4 crank position and the G28 engine speed sensors are all giving good signals so the ECU can fire the relay via pin 3/55. Seems like you have the injectors wired to a switched 12v line, perhaps not through either a relay OR fuse. Something is not correct in my opinion.

[Durr McDanks]

haha English is my first language and I speak French as well, but I am seriously terrible at electrical/ wiring concepts. I strive to comprehend it better hence all of the questions. Sorry and thank you for helping me out.

Ok, have some goods and some odd news. I am getting 11.5v switched power at pin 27 so thats all set. But the odd thing is when I have the ECU connected and when I just have the key turned on and NOT cranking I still get 11.5 volts at the fuel injector connectors. And pin2 of the hall sender is exceeding 5v for sure its in 10v range. Any thoughts?