Mk2 1.8T Conversion - Starting Issues

[Yohan87]

Afternoon,

Posting this here because this forum seems to have the most technically clued up people around when it comes to 1.8T's so hopefully you can help.

My friend has fitted a 1.8T AUM engine in to a Mk2 Golf and followed guides to allow retention of the OEM Bosch management system.

At this point in time when you turn the ignition on the fuel pump primes and we've confirmed there is fuel reaching the fuel rail. When you turn the key to start the car the engine turns over smoothly but doesn't even sound like it's trying to fire, no coughing or spluttering, just turning over.

We pulled all the coils out and when turning it over with the coils out they were all sparking at first, but then only one kept sparking as it was cranking.

We measured the voltage at the injectors and are getting approximately 3.4v - 3.6v at each injector.

We also measure the voltage at the coil packs and we are getting 12v to the black/purple wire on the coil plug (0v on the other three wires) when on stage 2 ignition, and 9v when cranking on black/purple and approximately 0v - 0.1v on the 3rd and 4th (non brown wire).

It seems like we are so close but are stumped as to what it could be.

Any advise appreciated.

Thanks

 

[<tuffty/>]

Which ECU and is it DBW? AUM is ME7.5, wideband, DBW, VVT etc...

<tuffty/>

 

[Yohan87]

Which ECU and is it DBW? AUM is ME7.5, wideband, DBW, VVT etc...

<tuffty/>

That's the one.

 

[Scullies]

Is the fuel pump getting power while the engine cranks over? Fuel pressure in the rail at engine crank?

Thats my 2 cents

 

[<tuffty/>]

Any fault codes seeing as it ME7?

<tuffty/>

 

[Yohan87]

Any fault codes seeing as it ME7?

<tuffty/>

I'd imagine loads but we haven't wired up the diag port yet. That's our top priority now.

 

[<tuffty/>]

I'd imagine loads but we haven't wired up the diag port yet. That's our top priority now.

I would do that first... then get back to us

...might also be worth mentioning exactly what you have done to get this engine in as tbh just saying you have an AUM in a Mk2 Golf doesn't really help....

<tuffty/>

 

[Yohan87]

I would do that first... then get back to us

...might also be worth mentioning exactly what you have done to get this engine in as tbh just saying you have an AUM in a Mk2 Golf doesn't really help....

<tuffty/>

Will do.

I'll get my mate to join up as it's his baby and he has a much better understanding of it

 

[<tuffty/>]

Using ME7 means a lot of stuff needs to be wired in or coded out as its tied to most of the electrical systems of the car... 90% of these conversions fail epically on wiring alone...

<tuffty/>

 

[JUS3IN]

What about immobiliser got the key halo ect? Clocks? All paired with the ecu?

 

[Yohan87]

What about immobiliser got the key halo ect? Clocks? All paired with the ecu?

R-Tech defeated the Immo, clocks are Mk2 clocks and Mk2 key.

 

[BENJAMIN]

Blue yellow wire at the maf, check that for 12v when cranking.

Wire up the obd port and determine of you're seeing rpm when cranking using vcds.

Another silly thing people do is putting the fuel pipes on the wrong way round. Blue pipe is return, black is feed.

The red/green wire on the 20v loom requires permanent 12v (originally would of been in a brown square connector that plugs onto the scuttle of the donor), do not connect this to the red/green on the mk2 ecu power loom, guides and wiring diagrams suggest this is a permanent 12v feed, it rarely is, connect it direct to a good permanent 12v source like the battery!


I do a lot of oe management conversions and it'll be something very simple!

 

[Yohan87]

Blue yellow wire at the maf, check that for 12v when cranking.

Wire up the obd port and determine of you're seeing rpm when cranking using vcds.

Another silly thing people do is putting the fuel pipes on the wrong way round. Blue pipe is return, black is feed.

The red/green wire on the 20v loom requires permanent 12v (originally would of been in a brown square connector that plugs onto the scuttle of the donor), do not connect this to the red/green on the mk2 ecu power loom, guides and wiring diagrams suggest this is a permanent 12v feed, it rarely is, connect it direct to a good permanent 12v source like the battery!


I do a lot of oe management conversions and it'll be something very simple!

Thanks Benjamin

 

[Gloves]

Hi folks...thought I'd sign up here as well (it's my motor that Yohan's been helping out with) seems to be some really good advice on here.

Thanks for all the tips so far!

I'll put up a proper intro thread later but in the mean time.....I hooked up the diagnostics port last night to see if it would shed a bit more light on the matter and after I cleared all the codes then scanned again this is what I was left with:

4 Faults Found:
17931 - Crash Signal from Airbag Controller
P1523 - 35-00 - Implausible Signal
18057 - Powertrain Data Bus
P1649 - 35-10 - Missing Message from ABS Controller - Intermittent
18058 - Powertrain Data Bus
P1650 - 35-00 - Missing Message from Instrument Cluster
18056 - Powertrain Data Bus
P1648 - 35-00 - Failure
Readiness: 0110 1101

First three are explainable as I don't have any of that fitted so I'm guessing it's the last one that's giving me the issues? Seems to be very little on the net about it....wondering if anyone able to shed some light on whether this is whats preventing the engine from starting?

Thanks

 

[BENJAMIN]

Hi folks...thought I'd sign up here as well (it my motor that Yohan's been helping out with) seems to be some really good advise on here.

Thanks for all the tips so far!

I'll put up a proper intro thread later but in the mean time.....I hooked up the diagnostics port last night to see if it would shed a bit more light on the matter and after I cleared all the codes then scanned again this is what I was left with:

4 Faults Found:
17931 - Crash Signal from Airbag Controller
P1523 - 35-00 - Implausible Signal
18057 - Powertrain Data Bus
P1649 - 35-10 - Missing Message from ABS Controller - Intermittent
18058 - Powertrain Data Bus
P1650 - 35-00 - Missing Message from Instrument Cluster
18056 - Powertrain Data Bus
P1648 - 35-00 - Failure
Readiness: 0110 1101

First three are explainable as I don't have any of that fitted so I'm guess its the last one that's giving me the issues? Seems to be very little on the net about it....wondering if anyone able to shed some light on whether this is whats preventing the engine from starting?

Thanks

I think it's just because your can hi/Lo wires understandably don't go anywhere ( the pair of orange wires that are twisted together)


Go into measuring blocks and see if you're registering an rpm signal whilst cranking.
Does your +12v supply to your coils, injectors, maf, ecu stay 12v whilst cranking? Mk2 golfs have a load reduction relay that removes power from various circuits during cranking, if one of your power feeds is tapped into one of those circuits it won't start.

 

[Gloves]

Thanks Benjamin - appreciate you help. Notice you have a mk2 1.8T (for your signature) as well. Did you go the standard management or stand alone route?

You are right - my hi/lo CAN Bus wires are currently not connected.

Getting an rpm reading, was a little low (160) so I put jump leads on from my other car but still no joy.

Checked everything was getting 12v but my injectors only see ~3.45v each whether on stage 2 ignition or cranking - wondering if this could be my problem?

Also now getting a bunch of new codes which sounds like something common is going to earth when it shouldn't??

10 Faults Found:

18056 - Powertrain Data Bus
P1648 - 35-00 - Failure
17633 - Fuel Injector for Cylinder 1 (N30)
P1225 - 35-00 - Short to Ground
17635 - Fuel Injector for Cylinder 3 (N32)
P1227 - 35-00 - Short to Ground
17636 - Fuel Injector for Cylinder 4 (N33)
P1228 - 35-00 - Short to Ground
17634 - Fuel Injector for Cylinder 2 (N31)
P1226 - 35-00 - Short to Ground
17834 - EVAP Purge Valve (N80)
P1426 - 35-00 - Open Circuit
17955 - Boost Pressure Regulation Valve (N75)
P1547 - 35-00 - Short to Ground
17526 - Oxygen (Lambda) Sensor Heating; B1 S2
P1118 - 35-00 - Open Circuit
17938 - Camshaft Timing Adjustment
P1530 - 35-00 - Short to Ground
17697 - Boost Pressure Control Valve (N249)
P1289 - 35-00 - Short to Ground

Readiness: 0110 1101


On the off chance any one is super clued up on exact wiring connections, this is how mine currently stands:

T6-brown connector
pin 1 -black or black/purple 15 amp fused switched live 15 to ecu T121/3 (g1 pin 4, needs fuse)
pin 2 - purple/white ecu T121/65 to fuel pump relay earth (g1 pin 3)
pin 4 - red/green 20 amp fused constant positive 30 to ecu T121/62 (Y pin 4, needs fuse)
pin 5 - blue/yellow fused 10 amp from fuel pump relay (g1 pin 10, needs fuse)

T14a - 14 pin connector near battery
pin 4 -purple coolant temp sensor (214) Y/M (G2 pin 3, requires resistor to read correctly)
pin 5 - red/purple 10 amp fused switched live to injectors (183) ( Z/1)
pin 6 - yellow/black fused 10 amp from fuel pump relay (g1 pin 8, needs fuse)
pin 7 - brown earth (204) (197) (Earth to chassis or battery -VE)
pin 9 - brown/white earth for senders (G1 pin 6)

T10W -White connector
pin 4 - white/red ecu T121/39 to clutch pedal switch (Clutch pedal switch in car)

T10 Orange
pin 1 - grey/white to ecu T121/43 (229) ( diagnostics K diag port)
pin 2 - green/red to ecu T121/81 (Tach signal from ecu via tach adaptor to G1 pin 12)
pin 6 - blue/white ecu T121/54 to speed signal in dash wiring (Hall speed sensor on clocks W pin 1)

 

[BENJAMIN]

Not a problem. Yeah it was indeed on oe management, I run a company specialising in this kind of thing so have done many of these.

Are you measuring voltage across the 2 pins on the injectors? You need to measure the live pin(red purple) to earth not across.

Your connections look good except injector feed to z1 sometimes doesn't work. Do you have a short red jumper cable fitted on the back of the fusebox?

Try joining your red purple wire to g1 pin 8, to test.

Be sure to erase the codes before turning the engine over or it probably won't start anyway.

 

[Gloves]

Not a problem. Yeah it was indeed on oe management, I run a company specialising in this kind of thing so have done many of these.

You must have so much patience! I'm really comfortable with anything mechanical based just wiring really confuses me!

Are you measuring voltage across the 2 pins on the injectors? You need to measure the live pin(red purple) to earth not across.

The 3.45v was measured to earth not across. Maybe this links to the point below with z1 not working properly......

Your connections look good except injector feed to z1 sometimes doesn't work. Do you have a short red jumper cable fitted on the back of the fusebox?

Try joining your red purple wire to g1 pin 8, to test.

Be sure to erase the codes before turning the engine over or it probably won't start anyway.

Jumper cable is fitted. I'll try the connection to g1 pin 8 next.......cheers!

 

[Louis_Cleaver]

I know this is old.....I have the same issue implanting into a mk3...
don’t suppose you recall the solution ? Mine has same voltages etc as above and will start with easy start in the MAF, it’s also has all the same error codes?