Step 5. Engine and ECU change from 2.0 FSI to GTI

[DeWet]

I bought my cheap hail damaged golf 3 years ago I started looking for performance improvement options.
When I found a person selling off GTI parts on gumtree I jumped at the opportunity to get the suspension and HID headlights.
Since he also had the cylinder head and ecu I increased the scope of my dream.

Because of IMMO I first tried to read and flash the chip on the ECU and after frying 2 ECUs I kinda gave up.

Looking at replacing my cluster with the newer white one I managed to get Marin from the US to also IMMO code up a GTI ecu so that my existing ECU, new cluster and the GTI ECU would work with the new key transponders he provided.

Removing valves from the cylinder head I noticed all of them were bent so I had to replace valves and skim head before adding new valve stem seals

Waiting for the opportune moment to change the engine was a pain but had to be done as this is my daily driver.
3 days of annual leave would do it, I thought, but since removing the old cylinder head, manifolds and exhaust with ALL the lambda probes took a while and then after getting all the way to the charge pipe that connects to the throttle it showed me that I would need to replace the oil filter housing too

Another order from VW and another week of wait but then finally managed to get all the engine work done and car reassembled.

Engine turned over but wont start which get me to look at error codes.
Too many to mention which pointed to wiring issues and the had to draw up a comparison between my BLX wiring and the new BWA wiring of the T94 ECU connector( the 60 pin connector was wiring from the cylinder head so it was not my old wiring so didnt need anything to change).
One 12v 87a wire that shows on BLX and BWA diagram is missing from my wiring harness so left it open for now.

Another week of re-pinning T94 while scanning and sorting out errors it also lead me to the T14a connector where I had to do more changes.

I think I covered everything(except the missing earth pin2 which I ordered from DigiKey now to add when it arrives)

 

[DeWet]

I had to do a lot of hose mods to get everything connected.
Turbo oil feed is from a vdo connector I added to the oil pressure sensor on the oil filter housing.
I added the electric coolant pump but havent wired it up yet but will add relay and connect it once I get the engine going properly.
The car starts, idles for like 4 seconds and then dies.
From scans it looks like I have a battery/alternator issue and the pressure in the fuel rail is way to low making me think the hpfp need to be replaced.
I'm hoping that adding the missing earth pin2 to the ecu will sort out some errors and will try get an alternator and buy a new battery.

 

[DeWet]

After replacing the alternator, battery and adding the missing earth connection to T94 pin 2 the car still had error codes thrown.
I redid the earth connection point of the engine wiring harness near the vacuum pump and replaced the fuel pump controller and the errors were gone with ignition on but not started.

This left me with the high pressure fuel pump and the in tank pump to sort the starting then dying issue.

Since my car worked befor the change I assumed the in tank one was ok so ordered a replacement hpfp.
Fitting it it was still the same so down to my last hope.

I have a spare Audi A1 in tank pump so thought its worth a try........after fitting it the car did the same thing on the first attempt but then it started and ran probably a minute or so before dying.
This is a good enough indication for me so ordered a tank pump from a gti and waiting for delivery.

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[DeWet]

So after this engine started but still died after a couple of seconds. Replaced the high pressure fuel pump with no change.
I then tried a in tank fuel pump from an Audi and then the car started and ran for like a minute.

Thunking thats it I bought a 2nd hand pump from a GTi, installed it and tried it today.

Same thing, dies after a minute.

Tank pump only runs on ignition on and not when opening the door or when running.
I can keep it running if I ignition off and on again while driving to re pressurise the rail up to the hpfp.

Any ideas what the cause can be?

I did check the fuse a while back but since it works on ignition on I assumed that it shouldnt be the fuse.

Relay maybe?

Out of ideas here.

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[DeWet]

Everything checks out except for the LPFP. It only gets 12v when ignition ON and doesnt run when engine runs.

Checked fuses and all ok.

Not sure if my BLX configuration needs something else to get the lpfp to run on signal from the BWA ecu.......

For now just ran 12 straight to the pump to get it driveable for now.


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[DeWet]

With the car in limp mode and 7 errors being thrown I tried to knock them off 1 by 1.
Bought a 2nd hand MAF sensor as step 1, replaced it, cleared code and it just popped back.
Took my multimeter and tested connection on wires which tested fine until I tested voltage which only gave me 3.4V.

I desoldered the connection I made at T14a (BWA red/white to BLX yellow/red) and checked voltage. The 3.4V came from the engine wiring and the feed from the car's wired had nothing.

Checking the wiring diagrams it led me to fuse 27 which im the car was empty. Added a 15A fuse, tested and it got 12V with ignition on.

Soldered wires back together and cleared error codes which stayed cleared.

Tested this morning and limp mode is gone and my car finally has GTi performance

This conversion is not recommended for people that dont have perseverance and a hint of stubbornness

Thanks for all the input from this forum and via email ehich made this possible.

Where to from here you ask?...........already have boot/trunk floor, rear frame with haldex and propshaft, propshaft mountings, wiring, yaw sensor for 4 motion conversion.
I think I only need golf mk6 r transmission/gearbox and ABS controller to make it work. I hope

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