Hi, my problem: 1990 syncro 2.1 petrol. it was running and just stopped.
so far I have replaced coil and the distributor( cheaper than a new Hall sensor) sent the ECU to be checked, all good. I feel the only thing left is the crank sensor, if it has one or is that the hall sensors job?? I have fuel to the injectors. Anyway Im at the end of my tether. any suggestions. thoughts , ideas before i get it towed to a mechanic. aslo any recommendations for mechanic who knows T3’s in Tasmania,.
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Hi Michael.
Welcome to the forum.
You could try Andrew Robinson Automotive in Derwent Park.
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So you have no spark but you have fuel…have you tried your ignition switch?
You can hot wire it to test that theory.
Thanks Scott, haven’t checked ignition switch. thought if it cranks over it would be ok. ‘hot wire it’?? keen to be educated on how to .
Any luck with Andrew Robinson?
just trying to exhaust all my options before trying Andrew. bit out of the way, I live near Launceston.
If you get stuck, there’s Peter Murfett in Ulverstone.
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Hi Micheal,
This is what I found on the Samba.com:
Since you car cranks you can add to your confidence level by running a jumper from the coil positive (black wire) to the terminal on the rear of the alternator, then crank it. It should start. If it does, I would just replace the switch. Be careful to connect your jumper wire to the coil first, then the alternator. That will avoid a spark at the coil which if it makes it to the coil negative (green wire) can theoretically damage the ignition computer.
As for actually testing the ignition switch, you need a test light or a VOM. I recommend a test light (get a good one) as a very useful addition to your tool kit. If you look at the back of the ignition switch (looking up the by the steering column) you should see 3 rather large wires. There may be more wire, but the larger ones are what you’re interested in.
Assuming your battery is charge and you test light/VOM is properly grounded, the large red wire short have power with the ignition switch off. Red wires on VWs (original wiring) are always unswitched power from the battery.
Turn the key to the ‘on’ position and check the black wire. It should now have power. Black wires on VWs are always ‘hot’ when the key is on. This is the circuit that powers the ecu, coil, fuel pump relay, etc. If this doesn’t light up then ‘wiggle’ it and see if if does. This is the wire that I suspect is casing your problem.
With the van in neutral and the the switch in the crank position the red wire with the black trace (I’m working from memory here so you might double check the wiring diagram) should light up. Since you van cranks, we know that this works. Perform this test again while checking the black wire. If the black wire looses power while cranking then this helps verify the faulty switch. It may dim a bit, but it should still light up in order to allow the coil to fire.
wow. Thanks Scott for taking the time to provide this info. the car is at my sons. hopefully I can get to it soon to try your Very thorough recommendations. I will report the outcomes when completed… thankyou…fingers crossed
Had a similar problem last year & found that one cable within the wiring loom from the hall sensor had broken in a position approximately 20mm from the distributor. Probably a good idea to check continuity of the wires within this loom. Good luck.
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Thanks Matt, I now have a few things to check/confirm. Just need to find the time!! work gets in the way of a lot of things.
Hi Scott, finally got to the van to perform your checks.Tried power from alt to coil,cranked but no go.(with key on there is 12 8 volts at both terminals of coil) Checked ignition switch. All good except voltage at black wire when cranking engine . Reading of 11 volts.I have no power at the hall sensor wires which according to my research I should have.
Any thought/ comments/ ideas appreciated.
Anyone know of a good web site for wiring diagram.
Thankyou
If you’re handy, you could make one of these
TheSamba.com :: Vanagon - View topic - Hall Effect sensor tester
TheSamba.com :: Vanagon - View topic - Digifant, Testing Hall Sender
Hall sender tester (will not test your wiring though)
This is an excellent resource
Workshop Manual Volkswagen Transporter 1980> Digijet, Digifant Fuel Injection and Ignition System
Bosch Digifant workshop manual - it’s a little more detailed than what is in the Bentley manual even though they cover the same system.
This is a good tool, but it is limited in the information it provides in fault finding (more about maintenance)
Shoebox Electronix
They used to have a very good user guide (it was also on Vancafe web page), but I can’t find it currently. I have a hard copy, but not an electronic one.
In addition to what others have listed to check, a great starting point is confirming all earth wires are connected , clean, and making a good connection. That is both for the battery (and chassis connection) and at the engine to chassis.
Next one would be check/clean all connections in the EFI system. I use the electrical cleaner/spray and compressed air gently.
Given the tests you have done, and if the wiring checks out, I think the idle control unit (behind the RH tail light) can also cause issues.
Vanagon Digifant System - Van Cafe
There are a few knowledgable people on KombiClub if you are on there also.
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Thanks Richard. I have cleaned and checked all the earth connections. i think the centre wire in the loom connector to hall sensor is supposed to be live with ignition on. this wire ,I think goes to the idle contol unit, But no good thinking, hence the request for wiring diagram. i will persist for a bit longer before it will have to be towed to a mechanic.
The circuit diagram in the Bentley covers multiple pages, I don’t have an electronic copy, not sure if there is a diagram online
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Sounds like a hall sender failure to me.
Do you have a spare dizzy with good hall sender or know someone with one?
Where in Australia are you?
Scott,. I have a new distributor complete with Hall sender from J Kampers installed. I would hope that being brand new it would be good,but??
I have installed new dizzys before and they have been dead as caused by a hall sender that is faulty.
Have you installed it 180 degrees the wrong way?
I have done that too accidentally with your exact symptoms.
Try pulling it out again and ensure that off-set lug at the bottom fits into the corresponding groove in the base of the hole it goes in.
Best of luck.
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well, it’s been at mechanics for 2 weeks now. was in two minds… 1- hoping they would find something simple…2 -hoping it would be something more technical so I wouldn’t look like a d…head. they are leaning towards a faulty ECU which was sent away through mechanic to be checked. they reckoned it was not faulty. watch this space
Well, computer back, plugged in and we have lift off. purring like a kitten!
Bit annoying that they never diagnosed it correctly the first time…
lot of lessens learnt, but happy its back in action.
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