Club 80-90 Forums

Hi,

Got myself a little problem with engine not starting.

I have a 1983 VW T25 Westfalia Campervan with a Mk1 Audi A3 1.9 TDi (AHU 39****) in her.
Had her MOT'd - flew through.
On my way home, had nothing on the foot pedal, but engine was still running.
Then the pedal worked & a puff of smoke came out the back - think it was white/grey, figured it was diesel burn off. This did it for 2 or 3 more times before I got home.
Tried to start her up over the weekend, with no joy. Will turn over a good'un, but WILL NOT fire up.

Call to the AA

Out came the man, used some start spray and she fired up, was lumpy, then died. This happened a couple of times then wouldn't fire up again.
AA man suggested the potentiometer ??, then he suggested the EGR valve, then he suggested the MOT center have stuffed the engine, then offered to tow me to a garage.

Called over the 2 guy's who usually look after my mechanical needs to take a look.

They've just spent nearly 2 hours looking over her,

We've checked.........
She's getting fuel,
She's getting air,
She's had the injectors bled,
There is power getting to the glow plugs & the relay is clicking in.
The diesel solenoid is letting fuel through,
The fuel is diesel not petrol,

She just will not fire up.

They've gone off for the weekend to do some research and will get back to me when they know more.

In the meantime, I thought I'd do some asking of you guy's.

Is there anybody out there that has experience of this?

Please help

I have very limited experience with diesels, and with old tech, but here goes:

Injection pump producing pressure ? (presume so based on the "injectors bled" comment
Timing of the injection pump ?
Injector pipes properly tightened after bleeding ?

Have you tried searching other Audi / VW forums ?

Hi,

Yes to all.

I've posted my dilemma on 2 other VW/Audi forums.

It has been suggest that we swap out the fuel pump with a more 'mechanical' version thus by-passing the ECU altogether.

Good idea you think?

Burt

I don't know.... getting out of my comfort zone here, but I wouldn't generally start swapping fundamental components out.

Diesels are supposed to be easy - compression, metered fuel at the right time, unrestricted air > engine running

Mmmmmmm.......I wasn't sure either to be honest.

Is it easy to add a diagnostic socket to an existing ECU? My wagon doesn't have one. I guess if it were possible to 'chat' to the ECU, then it might actually tells me what it needs - if its possible. Probably cost mega ££££££

There's an idea.

Who did the conversion ?

An engine of that age will have had an OBD socket in the original loom, so if done properly, you should still have the OBD socket. Look at A3 wiring diagrams and looms to see if you can find it by physically following your loom. Or ask the converter

Have you checked the timing belt

https://www.myturbodiesel.com/wiki/timi ... i-removal/

This is what was left on the cam belt on a broken Polo I bought - nothing showing on OBD with this though

Naa, hasn't got one.

Spent ages yesterday looking all over fo one.
Don't know who did the conversion - just that it was a garage in Ashford. It was done before we bought it.

It has run very well & only let us down literally once or twice in the last 5 years - but to give an example of their work, they joined the Audi manifold to the VW rear box with a 7-up can & jubilee clips.

Not a bad Macgyver job to get you home, but not as permanent solution.

Where can I get a wiring schematic for this engine?

You'll be better off on the forums that use the engine as original fitment, though I came across this earlier when I wanted to be sure it would have had an OBD port

https://www.google.co.uk/search?newwind ... -GvvC9n_M:

Did you check the timing belt ?

Does the AHU have the round screwed connection to the fuel pump wiring harness? I think I would be looking there if it does for a "pooh" connection-green verdigris on the connection pins etc.
Think the OBD socket is an easy fit if you have the correct pin out diagram(I don't) for that year of donor engine and from memory will only be 3 wires max.
(obviously you need to obtain a OBD socket first but have seen them on ebay in the past)- sorry cannot be any further help as working in Turkey at present and am away from my own van.

Dr TIM at Ultimate Engineering would be worth a shout for possible direction?

Copied from Brickyard Forum:-

http://www.haywood-sullivan.com/vanagon/TDI/" onclick="window.open(this.href);return false;

'97 Golf 68-pin pinout below, others may vary.

Conn. Ref Pin Function Wire colour
T68 1 Ground Brown 2.5mm
T68 2 Engine speed signal to dash panel insert Black/Green 0.5mm
T68 3 J397 Rad. Fan run-on relay (AFN only) Brown/White 0.5mm
T68 4 N146 Metering adjuster (injection pump) Brown/Yellow
T68 5 N146 Metering adjuster (injection pump) Brown/Yellow
T68 6 Glow plug heater low heat output relay Black/Blue 0.5mm
T68 7 G149 Modulating piston movement sender Grey/Green
T68 8 G28 Engine speed sender Black (Shielded)
T68 9 MFA fuel consumption signal to dash panel Lilac/white 0.5mm
T68 10
T68 11 G80 Needle Lift sender (injector 3) Blue (Shielded)
T68 12 G80 Needle Lift sender (injector 3) Grey (Shielded)
T68 13 G70 Air Mass Meter Brown/Red 0.5mm
T68 14 G62 Coolant temp. sender Blue/Brown
T68 15 G79 Accelerator position sender White/Blue 0.5mm
T68 16
T68 17 F36 Clutch Pedal switch White/Red 0.5mm
T68 18 Auto Box only
T68 19 G70 Air Mass Meter Red/Green 0.5mm
T68 20 F47 CCS Brake pedal switch White/Yellow 0.5mm
T68 21
T68 22
T68 23 J317 12v current supply Black/Yellow 2.5mm
T68 24 Ground Brown 1.0mm
T68 25 N18 EGR Valve control Brown/White
T68 26 Glow plug heater high heat output relay Black/Brown 0.5mm
T68 27
T68 28 Air Conditioning system only Brown/Grey
T68 29 G149 Modulating piston movement sender Lilac/Black
T68 30 N146 Metering adjuster (injection pump) Brown/Yellow
T68 31 Auto Box only
T68 32 Auto Box only
T68 33 Sender ground in engine wiring harness Brown/Blue 1.0mm
T68 34 E45 Cruise control switch Blue/Grey 0.5mm
T68 35 E45 Cruise control switch Red 0.5mm
T68 36
T68 37 Air Conditioning system only Green
T68 38 Terminal 15 (Ignition) Black 1.0mm
T68 39 GROUND (Diag: Alternator W terminal or DF) BROWN (Diag: Red/Black 0.5mm)
T68 40
T68 41
T68 42 J317 supply relay control Black/Lilac 0.5mm
T68 43 Vehicle speed signal from dash panel Blue/White 0.5mm
T68 44 Brake signal (L brake light bulb) Black/Red 0.5mm
T68 45 J317 12v current supply Black/Yellow 1.0mm
T68 46 Ground Brown 1.0mm
T68 47 N75 turbo pressure control Red/Blue 0.5mm
T68 48 Glow period indicator to dash panel Blue/Green 0.5mm
T68 49 N146 Metering adjuster (injection pump) Brown/Yellow
T68 50 J52 glow plug relay control Yellow/Blue
T68 51 N108 Commencement of injection valve Brown/Black
T68 52 G149 Modulating piston movement sender White/Green
T68 53 N109 Fuel shutoff valve control White/Black
T68 54
T68 55 G79 Accelerator position sender Grey/Red 0.5mm
T68 56
T68 57 G79 Accelerator position sender Yellow/Green 0.5mm
T68 58
T68 59
T68 60
T68 61 Immo J362 (W-Line) (was K-line on non-immo ECU) Grey/White 0.5mm
T68 62 G79 Accelerator position sender Green/White 0.5mm
T68 63 G81 Fuel temperature sender Yellow/Black 0.5mm
T68 64 G72 Intake manifold temperature sender Blue/Yellow 0.5mm
T68 65 G79 Accelerator position sender Grey/Blue 0.5mm
T68 66 E45 Cruise control switch Black/White 0.5mm
T68 67
T68 68 J317 Terminal 30 current supply Black/Yellow 1.0mm

937carrera wrote:Did you check the timing belt ?

Hiya,

All the belts were replaced 2 years ago, only done about 2000K miles max. All belts look fine.

Trying to find an obd socket to wire in.

Try these for more help

http://forums.tdiclub.com/showthread.php?t=473545

http://forums.tdiclub.com/showpost.php? ... stcount=19

AHU has Bosch VE pump with EDC, so if the fuel is present at the injectors and the timing is good, then it should start. But would go to limp mode if any of the sensors go out (crankshaft position sensor, throttle position sensor, needle lift sensor, fuel temp sensor, pump quantity sensor)
The white/grey smoke you mentioned most probably means the timing is out.
I would start with checking if the timing is OK with being assured that the TDC mark is correct. The mainshaft pulley tends to wear and turn with time and also the late pump pulley with the 3 bolts if they not tightened correctly.
If the timing is surely OK, then I would try to swap the pump to a good known one. The timing advance plunger can also stuck keeping the pump in too advanced position.

ZsZ wrote:AHU has Bosch VE pump with EDC, so if the fuel is present at the injectors and the timing is good, then it should start. But would go to limp mode if any of the sensors go out (crankshaft position sensor, throttle position sensor, needle lift sensor, fuel temp sensor, pump quantity sensor)
The white/grey smoke you mentioned most probably means the timing is out.
I would start with checking if the timing is OK with being assured that the TDC mark is correct. The mainshaft pulley tends to wear and turn with time and also the late pump pulley with the 3 bolts if they not tightened correctly.
If the timing is surely OK, then I would try to swap the pump to a good known one. The timing advance plunger can also stuck keeping the pump in too advanced position.

Hi,

The white smoke came about when the AA man tried to start her using start spray. The usual guys I use couldn't see a problem with how its all set up.
I replaced the crank position sensor this evening - easy 10 minute job, but still wont start.


Looking like I'm going to have to wire in an OBD port to get a diagnosis.

Randolf posted up a pin-out list - just need to know do the pin numbers go from left to right/bottom to top or which way?

Cheers for everyones help - this is seriously getting me down.

Burt

Another question,

If my camper has been starting 'lumpy' all winter, could there be a glow plug issue?
Is it possible, say for instance, she was starting on just 1 glow plug? I notice the Glow plug light stays on for bl**dy ages - it always has been a bit slow as far as I can remember, but now it takes ages.

Is it possible that all plugs have failed - so the no-starting issue?
There is voltage getting to the plugs, that been confirmed - but how do I know if they are actually working - or not?

Burt