Won't Start! + Fault codes

So I'm still trying to get the mk2 1.8T AUM to run....without any luck

I'm getting fuel to the rail and a spark from the coil (albeit a strange pattern/sequence)

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....anyone able to shed some light on whether this is whats preventing the engine from starting?

Thanks

 

You don't have the Instrument Cluster connected? I would connect that as its part of the immobiliser. They normally start and then cut out if it's an immob problem but no idea what would happen if the cluster is not connected. I would try it for sure!

 

I had the immob removed so that I could run the mk2 clocks.

I do have the mk4 clocks but no key and all the wiring has been set up to work with the mk2 interior loom and fuse box

 

so you get fuel and spark?

does it try to start? idle? not run at all?

 

I took the coils out and turned it over (whether that's a good or bad thing to do I'm not sure) and I was getting a spark in each.

I'm definitely getting fuel to the rail and the pump is running - whether the injectors are powering I'm not sure. Just thinking I could check the plugs after cranking couldn't I?

It just turns over, doesn't even sound like it's trying to start to be honest.

What voltage should I get at the injectors?

 

12V feed, and negative switched by the ECU.

I've not seen that fault before so could be the dashpod disconnected, compression ok on the engine? timing ok? do you get a crank speed via VCDS when cranking above 250RMP (if not could be battery/connections)

any other new faults in the system?

 

Not sure if making progress here....these are the latest findings.

So I checked RPM speed and it was around 160 so thinking the battery could be low I put on a set of jump leads from my other car. For some reason it wouldn't give me a reading in VCDS again but it definitely sounded like it was turning over faster....still no start though.

I have a feeling that it's my injectors that are the issue - I only get 3.45 volts at each - sounds like they're wired in series???? Would that be right?

Got a new list of codes as well now:

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

"Short to Ground" - sounds like something common to all going to earth when it shouldn't?!

 

becareful jumping it.

can you chuck some easy start down the TB and see if that helps make the engine catch and go?

Has the engine been sat for a while?

 

Yeah it has - a couple of years actually. Followed advice from a member on here on prepping it before attempting a start though.

I'll see if I have any easy start kicking about.

The pump is definitely priming - I'll have a look into this though. Thanks for that.

 

It will show short to ground when there is not enough power - the cabling & consumer

From the diagram I have 10 amp fuse feeding 12volt red/lilac wire
You using a converted loom? Everything connected, joints good?

 

Those first set of faults are standard for anyone running OEM management on mk2 clocks, it's the rest of the control units typically on the CAN network the ECU is no longer seeing/talking to. As long as it's been deimmob, those particular faults are nothing to worry about.

On the second set of faults, ignore the N80 fault, this is charcoal EVAP purge valve solenoid, no longer connected. 02 lambda B1 S2 is the downstream sensor, no longer connected.

The n75 valve should be faulty, along with the n249 valve (unless bypassed & unplugged), however these faults are not related to it not starting to ignore these for the time being. Camshaft timing, shouldn't be faulting either, again though I doubt this is the cause for your start fault.

So that leaves you with injectors! Strange they didn't appear the first time around and if you have unplugged them at any stage to test voltage with the ignition on, remember this will store a fault so make sure this fault code is a valid one & your not chasing a fault due to the above reason. Erase them & try starting, see what faults you have then, if any.

As above, you should have a 12v feed to all the injectors. ECU switches via earth. It's a big fat wire in the 14pin plug that is the feed wire to, difficult to give you direction on where to go back from there as it will depend on how you have wired it into the original fusebox.

Physically check you have the pump priming & are getting fuel to the rail by taking off a pipe at the rail & watching fuel go everywhere (bucket). Next, get on ebay & buy some noid lights. These go between the injector plug & the injector electrical connection & they flash when in the injector is switched, very easy way to see if your injectors are being switched without the hassle of back probing the plugs. You can have all 4 connected at one time to so you can just watch the light show if they're working properly. You can get a set of 4 for about 10.

I would start there, another tool I would invest in just to make 100% sure is OK - on similar principle to the above in that they light up in operation are some coil lights. They sit between the spark plug & the coilpack & light up again when voltage is passed through. A easy way to see if they are working & compare light output to determine a weak coil if required, cost roughly around 10 to.

Have you checked compression? If not, check that first.

HTH!

 

when testing for fuel at the rail, take the pipe off first before adding pressure/turning things on, saves getting soaked in petrol! lol

 

Folks - really appreciate all the help on this. If I ever get the chance to meet any of you there's a round on me!

Wasn't able to get out to the car again on Sunday so it's now a frustrating wait until Saturday before I can try again.

Classy6 - some excellent info, thanks. Set of noid lights sounds like they'll be extremely handy! (had never heard of them!).
Did you go for a set like THIS or just 4 of the same type?

Also have you got a link to the coil lights you used? Not quite sure what I'm looking for here.

Not carried out a compression test yet - have put this on the to do list.

Fuel test has already been carried out - it's fine. Jon P that lesson was learnt the hard way (system was off but still had a bit of pressure in it)

 

I learnt the hard way to, didn't even think whilst I was undoing a fuel line that i'd get a face full.

 

Those noid lights are cool. Can you run the car with them on?

 

I'm not sure if I've done this - which plug/wire is this?

 

Ah, know what one you mean. Yes I've got that plugged in (goes to number 12 in the second picture?)

Am I right in saying the ecu live comes from the T6 brown connector pin1, which in turn supplies this plug with a positive??