Vanagon Syndrome??? Totally at a loss

[pecksa]

The story so far….1991 T25 2.1DJ automatic

The van will (usually) start OK from cold and run for a period of time (5 miles to 37 miles as I found out last night) then it will either stumble to a halt if I stop a junction, or just cut out completely, even at speed.

This is the list of things I have worked through so far (or at least the ones I can remember)

1. Fuel pump and filter changed
2. Fuel pressure and flow checks
3. Injector operation and spray pattern checked
4. Engine bay earths remade
5. Air flow meter checked (it is one of the old flap that gets moved by the air flow)
6. Distributor cap, rotor arm, plugs and leads replaced
7. Coil voltage checked
8. Fuel injection (Digijet) ECU changed for a loan one from ATP (they could not find anything wrong with the original on testing.. but it was worth a try)

The original ECU is now going back in. The van started last night after loads of encouragement and we got it back on the drive from where the RAC left it when they recovered me again from another failed test drive.

No idea where to go next. Any thoughts would be greatly appreciated.

Thanks Andy

[syncroandy]

If I understand right it starts OK from cold, but then it goes wrong once its warmed up. Have you checked/replaced the engine temp sender ?

[mark]

WHS^^^^ temp 2 sender. and also clean all the electrical contacts with contact cleaner and a tooth brush takes a couple of hours. when i had a problem with over fueling i thought the same vanagon syndrome, but it is very hit and miss and you seem to be having a constant fault.

good luck with it

mark

[icosahedron]

How did you check the AFM? Vanagon syndrome is all about dirt lying on the upward facing potentiometer track inside the AFM. This gets caught between the wiper and track, the ECU gets the message that airflow has been reduced and reacts by reducing the fuel supply. Try cleaning the track if you haven't done so already.

[mark]

Vanagon syndrome is all about dirt lying on the upward facing potentiometer track inside the AFM. This gets caught between the wiper and track, the ECU gets the message that airflow has been reduced and reacts by reducing the fuel supply. Try cleaning the track if you haven't done so already.

i thought it was down to the wiper wearing the track and giving faulty readings and if you bent the wiper so it ran on a different part of the track this would cure it? personally i think its more than just the wiper wearing the track looking at the components in the vw fix.
there is a vw afm harness that can be fitted that is a cure and a 50p cure, how well the 50p cure works i dont know. i think the later 89 onwards have the upgrade fitted to afm internally.

http://www.telusplanet.net/public/gary2 ... arness.htm" onclick="window.open(this.href);return false;

http://www.westfalia.org/community/show ... -Meter-fix" onclick="window.open(this.href);return false;

http://www.members.shaw.ca/bilbo/WBafm.html" onclick="window.open(this.href);return false;

i spent hours reading everything i could find reguarding vanagon syndrome and in every case after the episode the van would restart first time. the temp2 sensor costs about a tenner from vw inc rubber seal ring and hairpin clip. is a five min job though you will get covered in coolant.

mark

[icosahedron]

The wearing of the track is the source of the debris that causes the problem. You can clean the track a number of times before having to resort to moving the wiper. This only becomes necessary once the wiper has worn through the resistive layer. Cleaning the track will leave a brown smudge on a white cloth. The capacitor modification reduces the amount of noise in the signal from the AFM and might offer an immediate fix, but the signal will only get noisier in future. No different than having a noisy amplifier volume control and then turning the treble control down.

[mark]

The wearing of the track is the source of the debris that causes the problem. You can clean the track a number of times before having to resort to moving the wiper. This only becomes necessary once the wiper has worn through the resistive layer. Cleaning the track will leave a brown smudge on a white cloth. The capacitor modification reduces the amount of noise in the signal from the AFM and might offer an immediate fix, but the signal will only get noisier in future. No different than having a noisy amplifier volume control and then turning the treble control down.

mark

[skippymoss]

Mine used to do something similar.
When you say it cuts out at speed, does it ever cut out when you have your foot on the throttle or just when 'coasting'?
Recently gave the wiring and connectors a really good clean and bypassed the digital idle stabilisation control unit.
Couldn't say for sure that this is what finally sorted it but it's been good as gold lately.
Good luck.

[pecksa]

Thanks for all the tips. I am starting to work my way through them, cleaning everything as I go.

Now not starting well even from cold...so I think we can knock the Vanagon Syndrome on the head.

Will keep you posted.

Cheers Andy

[rich broom]

it wouldn't be the ignition amplifier would it?

[callanish]

Hi
I spent £500 out of the udders of my cash cow and gave it to a garage who claimed to have a man on the staff who knew these vehicles inside out..........they fiddled and twiddled ........replaced leads cap and the like .....they stood in a huddle round my engine and scratched their collective heads and went oooooo when it cut out and wouldnt start again for 20 mins...........After they had tweaked my udders for the final time and said "well we think its better than it was"........i took it away, it broke down. WHAT SHOULD I DO?. new engine?
NO ....what i did is what i should have done to start with .I called Gasure made an appointment and took it to see Steve the magician. He worked his magic fitted a capacitor or something charged me so little that i decided he MUST have a case of beer for Christmas and guess what ...........completely cured the problem.
If you are totally at a loss get up to Chester. Steve will sort out your Vanagon Syndrome.

Andrew

[skippymoss]

Any chance you could tell us specifically what he did?
The suspense is killing me...

[callanish]

Hi
as i understand it the problem with this syndrome is caused by the airflow meter sending false signals to the engine management system which it didnt recognise causing it to shut down. The capacitor smooths out these issues and cures the problem..........since it has been done the engine tends to over rev a little when cold but i can live with that.
Steve is your man speak to him.

Andrew

[skippymoss]

Ta
I'll keep this bookmarked for when it happens to me!

[jojorose]

The story so far….1991 T25 2.1DJ automatic

Sorry looking for clues for my own wagon which is misbehaving. I have a 2.1. Petrol automatic, 1991. What does the DJ stand for. Are you diesel? In which case your solutions are no good for me?

jojo