HELP! 1.6l to 1.8T conversion wiring issues....

[Stan]

Hi guys, i need the help of a wiring guru.

I have a 2000 1.6 Golf AKL engine and am mid conversion in putting a 1999 Audi 1.8T AGU.

Yes there is a pending build thread....

I have the entire Audi subframe and changed the lot over, including ECU and its looms - a big enough job

However the plugs that go into the rain tray are slightly different - original being orange , brown and white, and new being orange , green and white. all but a few wies match, but I think that is where the trouble lies...

The engine cranks, but doesnt fire (should at least run for a few seconds even if the immobiliser is locking me out...).
Fuel pump doesnt run - but a hotwire to the pump and it does - fuel pump ok. Interestingly with a multimeter it shows only about 5 volts at the pump with the key on and cranking.

ah ha, you say - the fuel relay. Well it clicks with the key on and off - so not totally stuffed (and worked fine before the change...) - I will replace it anyway.

Any other ideas? Specific wiring diagrams for the 1.6 and 1.8 would be nice - but they need to cover the exact years and models as there were some wiring changes at about year 2000...

i have the Bently pdf for Golf mk4 - but it doesnt cover the 1.6 and it's 1.8 section wiring is inaccurate for the 1999 Audi A3.

I have access to vagcom if required, but havent used it before.

This car is so close, but now I'm going f#$king nuts and am dreaming about wiring, relays and cars that wont go.

What was changed into the Golf was the entire front subframe, ecu and the two main looms from the ecu.

Any help greatly appreciated

[Stan]

any auto elecs want to help me out, it's 90% there.

it's my daily driver as well, started this on leave and now it's over, wifey is not impressed

[stickshift3000]

Have you verified that all the basics are working?

Are the plugs getting spark? Is the ecu getting power? Injectors operating?

I realise these are basic things, but diagnosing this issue may be impossible over the net.

Nice project btw!

[grtuned]

If you have vag com erase faults then see what faults are still there this may be able to pinpoint which direction to take,
If you can upload log of faults to thread..

[h100vw]

1,8l Motronic (AGU)1.pdf

1,8l Motronic (AGU).pdf

One of these diagrams might be of use.

Gavin

[Stan]

thanks guys, I'll run some tests, log faults and see what happens next.

Thanks for the pdfs Gav!

[Stan]

Yes pump primes.
My suspicion is an earth issue as well , either off the loom or bad ecu earth. Thanks for the suggestions

[Shadow_Rusty]

If the fuel pump primes, and then doesn't run again, the car thinks it has full fuel pressure...
I don't think it's the fuel pump circuit you should be looking at, but rather the ignition/injector circuit...

If you plug a multimeter into the injector sockets, can you see a pulse when you crank the engine?

[Stan]

I tend to agree
Yes, I get 5 volts with ign on and flickering wirh cranking

[Jmac]

Fuel pump relay wiring different in the A3 to the 1.8T, different ECUs . 1.6 is SIMOS and Motronic for the AGU. Some major players on the relay go to different spots between A3 and Golf. Pm sent with wiring suggestion, ill only complicate matters if i post it here.
Jmac