Coolant sensor goes faulty it over fuels. should be able to see the temp on you obd reader think they end up going -20 on the reading
I think I might have found the issue. I have an earth connection mid way between the loom connection and the fuel pump relay. So I think that might have been causing issues. Have labelled it and will plug the loom back in tonight to check if that solves the problem
I have edited this post a few times, but now that the engine is up and running, this has everything i need to get my AGU running. Thanks to John Newman AKA RubJonny for the help as always! So i have decided to just write out all the connections for the AGU to CE2 here, it will be easier to spot the issue and might also be useful for others: I run a separate relay to power the ECU which is a 53 Relay, it is not the prettiest, but it works and its solid. Z1 - to Engine loom connection pin 5 30 - to fused ECU relay Pin 30- this then powers ECU pin 3 - so Permanant Live as its a live fed before the relay takes an action? relay Pin numbers 30 - fused Live from Fusebox Live 30 85 - Earth - Engine loom Pin 9, Earthed near the fusebox 86 - Goes to G2/4 87 - Goes to engine loom pin 8 and also ECU Pin 1 G1/1 - Empty G1/2 - outside air temp sender ground G1/3 - ECU relay power to ECU pin 4 G1/4 - Empty G1/5 - Ground to Cylinder Head G1/6 - Empty G1/7 - Empty G1/8 - Heated Oxygen sensor power - this merges into a single feed for my MAF and O2 sensor power and engine loom pin 6 G1/9 - Empty G1/10 - Empty G1/11 - Blank G1/12 - Tacho input G2/1 - Oil Temp (to a sender on the oil cooler/filter housing part number 049919563B) G2/2 - Outside Air Temp Sender G2/3 - feeds engine loom pin 4 (should be coolant temp sender) G2/4 - feeds to ECU relay 86 G2/5 - Empty G2/6 - Empty G2/7 - Empty G2/8 - Empty G2/9 - Empty G2/10 - Oil pressure (High Oil Pressure Switch to a sender on the engine (056919081 - oil pressure switch, 1.8bar, white)) G2/11 - Engine loom pin 1 - (Low Oil Pressure Switch (028919081H - oil pressure switch, 0.24bar, blue )) G2/12 - Empty T14a connection - Engine loom (agu) 1 - G2/11 (Low Oil Pressure Switch) - this is a black wire on the engine loom that has goes to a low pressure sender 2 - Empty 3 - Empty 4 - G2/3 5 - Z1 Power 6 - G1/8 7 - Earth for coilpacks - To the battery 8 - Coilpack Power - to ECU Relay 87, The 87 connection also runs to ECU Pin 1 9 - ECU relay pin 85 - Its the Earth for the Coolant Temp Sensor, can go to any earth point. 10 - Empty 11 - Empty 12 - Empty 13 - Empty 14 - Empty ECU connection: 1- Live from Relay pin 87 2 - Earth - just needs to be a solid earth point 3 - Permanent Live relay pin 30 4 - G1/3 6 - Tacho - rev signal 12 - MAF Pin 3 13 - MAF Pin 1 19 - Kiline for OBD Port 25 - 02 sensor 26 - 02 sensor 27 - Lambda Earth - can go above fusebox
car was all fine and running when i pulled the loom previously though, can imagine it would just break when laid up?
yeah on occasion it will for a few seconds. this is why i think its a wiring issue. Bad earths can play a big role in intermittent running
Got some errors on a scan now i can connect to VagCom, maybe my wiring is ok and i just have the issue with the throttle, i knew it was not making the noise like it used to. I did replace the clip for that connection, so likely got a wire the wrong way around? 17953 butterfly valve control malfunctioning 17973 butterfly valve control unit -J338 lower notice one does not reach 00670 - Throttle Position Sensor (G127) 06-00 - Signal too High 16507 butterfly valve potentiometers signal too largely
throttle body resolved, 2 of the tiny cables were reversed. Now it sounds and acts as expected... still no fire up though witht he MAF in...this might be down to none of the pipes being connected up with clamps, just loosly on and loads of VAC leaks.. With the MAF off, it ran!
The ecu relay is your main issue most likely. pin 85 of the relay needs earth. pin 9 on the T14a plug is the earth for the coolant temp sensor. Usually you would put the ECU live from one of the Y spades, but if you have a MK3 30-30b jumper this has connections on the back of it. You can also use G2/9, its unfused but isnt a big deal for this feed as its tucked up pretty safe in the loom. If it helps put your mind at rest MK3 and Corrado ECU permanent live is unfused wire from Y spade or G1/9. can also splice a wire direct to the 30-30b jumper if you like will work just fine. More info on ECU live later G1/10 is ecu relay feed, not really where you would usually tap your electric windows into. electric window relay trigger should be D plug, 8,9 or 11 G2/4 is ignition live output, you mention fuel relay 86? did you mean ECU relay, that would make sense T14a: 1 - unused unless running electronic speedometer 7 - earth for coilpacks -> battery 8 - coilpack power -> should be fed from an ecu relay along with ECU pin 1. assume typo same as above 9 - earth for coolant temp sensor, can go to head, battery or chassis all fine ecu pin 2 I put to battery just because, but on the MK4 it earths to the chassis near ecu. can earth above fusebox if thats closer, just make sure its a decent earth point. ecu pin 27 isnt an ECU earth, its the earth for the lambda probe heater For ECU relay, you can run it like this: Y spade -> 15a fuse -> ECU relay pin 30 and ECU pin 3 85 - earth 86 - ignition live 87 ECU pin 1, T14a/8 this is just like the DBW looms are from the factory and means you can use 1 fuse for both the ecu live and coilpacks.
Yeah ECU relay, not sure why i was calling it the fuel relay. Just confusion i think. Thats good info John, thank you again! will updaye my list above. i'm sure i'll need to re-visit it again at some point
Well the car is running reliably so back to wiring and just making that work in terms of routing a little bit better. The ecu to engine loom is fine but with the way i wanted to route the ECU relay to engine was a bit short. So i've extended it by about a meter or so, this should give me the slack i need to run it properly. Injectors have been swapped over Driveshafts in Intercooler plumbed in Battery relocated to the boot and working Live and Earth feeds to the battery to the boot
Getting there then Craig, it's all the little bits that take the time, and hiccups along the way dont help at all. Keep it up mate.
Been doing some bits but forgot to take many photos. Fusebox to engine loom extended just to make it all much easier to route internally. Engine loom looks much tidier now Battery cables ran but will need to decide on a new battery and how i'm going to secure it in the boot... i have got a false floor in there at the moment for the Sub, but i won't be running a stereo any more, so might re-make the floor and secure the battery to that. IMG_20201218_145924 by Laxadams, on Flickr IMG_20201218_151432 by Laxadams, on Flickr IMG_20201217_160620_758 by Laxadams, on Flickr
