Do I have vanagon syndrome and what is/are the cure/s

[Mr Bean]

Before anyone pipes up I did use wiki and it did kinda put me in the right direction but:
My E reg T25 2.1DJ (petrol) took us all round France last year but recently died after a short journey. After recovery I changed some bits and thought I had fixed it but it died again. I got recovered four times by a friend but our friendship is running a bit thin if I do it too often. The more you let it "cool down" the longer it lasts but if you keep trying to start it it fires up and stops straight away. It still sparks when the fault is on but (and I don't know if it is wishful thinking) the spark seems eratic/weak. The symptom is very similar to an overheating coil in the days before electronics. I have checked the fuel rail pressure and changed distributer, leads, ignition module, coil and tried running it with the ignition timing gismo out of circuit. I have good voltage on both relays and good earths as far as I can establish. I now suspect the ECU gismo but am concerned about just chucking expensive/hard to find bits at it and still not getting anywhere. I am wondering about any sensors which may be lurking in the backgound and causing this problem. I would love to see a schematic/functional diagram of how the whole thing ties together so I can trouble shoot it like in the pre-electronic times.

[Aidan]

changing things is one thing but you are better off checking them see the Bentley manual and do the digijet checks from thatall the diagrams/schematics etc are in that, slight variations as they (US) had a lambda and 1.9 but otherwise the procedure applies. I'd want to be sure the throttle switch, idle stab unit and fuel pressure reg were right, leads all correct resistance, ditto plugs and cap and arm, timing, vacuum advance/retard etc....fuel/air/spark. You haven't filled in your profile to say where you is so noone knows where you is to help point at local source....

[toomanytoys]

Have you fitted a new rotor arm???

Recently had a van that would run for 20-30 mins then cut out.. new rotor arm (yes checked all the other stuff and swapped this and that for known good ones...) seems to have cured it... Sometimes its the really silly things that do it.... But as Aidan says... Bentley gives some great diagnosis...

[Fritz]

Ken,,,,,,,

Before anyone pipes up

If you are in need of some help, for a start you are gunna have to be nice to us, a good number of us have been here for quite a while and most problems have a conclusion, so please be patient with us....

Regards,

Fritz,,,,,,,,

PS, my question : is your vehicle injected and running a Lambda sensor in the exhaust ?

[HarryMann]

Well..

1) You need a Bentley Manual

2) You need to terll us a bit more than this:

.. but recently died after a short journey.

Ok like a bad coil, but what is your description of what it does when it 'dies'..

There must be more to it than 'just stopping dead', surely?

=============

Vanagon Syndrome covers a whole multitude of things of course as there isn't really, nor ever was, ONE syndrome!
VS was an MV thing, US spec vehicles with the Digifant system

[Hacksawbob]

I had a faulty ignition control unit that gave those symptoms. The 2" square unit on the left wall of the engine bay stuck on a heat sink. Ideally you could borrow one to test, but good to have a spare anyway. I got mine from syncrospares.

[toomanytoys]

"vanagone syndrome" isnt as bad as "Syncronitus"

[Mr Bean]

changing things is one thing but you are better off checking them see the Bentley manual and do the digijet checks from thatall the diagrams/schematics etc are in that, slight variations as they (US) had a lambda and 1.9 but otherwise the procedure applies. I'd want to be sure the throttle switch, idle stab unit and fuel pressure reg were right, leads all correct resistance, ditto plugs and cap and arm, timing, vacuum advance/retard etc....fuel/air/spark. You haven't filled in your profile to say where you is so noone knows where you is to help point at local source....

Sorry as you can see I am a newby and I just got back from a damned house/cats/dogs/birds/grandson sitting task which has cured me of birds,cats. dogs, children and gardens and worse of all kept me away from the problem for nearly three weeks. I have done most of the stuff you suggest but as you say you could chnge almost everything and still finish up with the problem without prpoer diagnosis. I will fill in my profile soon but I am located between junction 7 & 8 of the A1(M) in Herts. What is the best source for the Bently manual and has it a reference number or similar so I can be sure to get the right one? Thanks to all for prompt response - I don't feel so lonely now!

[ermie571]

Ken,

think it will probably be one of these you need:
http://shop.justkampers.com/advanced_se ... 20683d4e5d

just a pointer.....when you next test your vehicle....keep detailed notes of what happens.....how fast, how long (miles and time) driving conditions....anything unusal (ie got a bit hot, hesitant, lack of pwer, buzzer of doom etc). Then take some time and put it in a post.

For ease of reading, it can be helpful to
1. use bullet points
2. short sentences
3. mention stuff that may not be obvious to you, but helps out those trying to give info over the ether

those that know on here are really good......but the more info you can provide, the more direct and relevant the assistance will be.

oh...and if you change stuff out....keep the originals....until you have identified the "naughty" part!!

take care, and hope you sort it soon

Em
x

[Mr Bean]

Ken,

think it will probably be one of these you need:
http://shop.justkampers.com/advanced_se ... 20683d4e5d

just a pointer.....when you next test your vehicle....keep detailed notes of what happens.....how fast, how long (miles and time) driving conditions....anything unusal (ie got a bit hot, hesitant, lack of pwer, buzzer of doom etc). Then take some time and put it in a post.

For ease of reading, it can be helpful to
1. use bullet points
2. short sentences
3. mention stuff that may not be obvious to you, but helps out those trying to give info over the ether

those that know on here are really good......but the more info you can provide, the more direct and relevant the assistance will be.

oh...and if you change stuff out....keep the originals....until you have identified the "naughty" part!!

take care, and hope you sort it soon

Em
x

Bentley manual on order.
1988 2100cc petrol watercooled DJ(TCH) goes a dream for 6- 10 miles until fault developes then gives up the ghost whereupon it cuts dead as if switched off.
Although after I changed the distributor it did twice that run once without failing but then failed on the second trip.
Once the fault is present it fires up but stops straight away.
The time it will run subsequent to that is proportional to the time left to "cool".
I say "cool" as this is what I would expect with something like an overheating electrical/electronic device.
I think the time is getting less as I managed to induce the fault by running it stationary for about 15mins.
It still sparks with the fault but maybe not so good although it is only spinning on the starter.
I conneced a pressure guage to the fuel rail and it held around 2 bar both before and after the fault is present.
I bypassed the idle Stabilisation unit and the fault remained.
Both fuel pump and current supply relays are good and up at 12V
All earths are good as far as I can see.
Parts replaced so far: Leads, rotor and cap, distributor, Ignition module, coil.
Parts still suspect: ECU and any connectors or sensors I don't know about
Parts unlikely: injectors - simultaneous falt unlikely...
I am going to run it with a four trace oscilloscope inductivelly sensing the sparks plug and injector leads today if I can induce the fault stationary again without risking another recovery. I might get a clue from this. (Don't tell me- all this science and it is probably a loose connector somewhere!!!!)
Cheers
Ken

[HarryMann]

Parts replaced so far: Leads, rotor and cap, distributor, Ignition module, coil.

Ignition module? What about the Hall-sender in the dizzy though...
They fail with heat, known to fail after a fire in engine bay and with age.

Might be an earth upset as it heats up, but doubt it very much... so if you haven't subbed the Hallsender someone will lend you one for a trial, I'm sure.

[syncrosimon]

It would be worth looking at the Air Flow Meter. Pry open the black box where the plug is, and clean the scaletrix style current track. Then check that the figures as given in Bentley are the same as your own readings.

This is the engines main input for running the computer and dirt on the track can cause a total loss of resistance, which makes the ECU think you have taken your foot right of the power. As this is an electrical fault it stutters very suddenly.

Even if you think your earths are good, put an extra in, all the information that the ECU processes are changes in resistance, which faulty earths can play havoc with.

The AFM, once unbolted from the air-box is a standard Bosch part used in other similar size an age VW.

The wiring has to be in tip top condition, any furry corroded connectors will upset the engine.

A rolling road diagnostic will analyse your sparking system. Can be money well spent, if the fault shows up.

[Mr Bean]

One went in with the new dizzy. I didn't mind buying stuff like the dizzy,coil,ignition module and leads as these are easy to carry as spares when touring. By the way I couldn't get the fault to occur again so it looks like some more recoveries by my (still?) mate are a posibility. Looking for posible intermittent connections I disconnected the water temp sender and that killed the engine for sure but afer I plugged it in again the cooling fan cut in seemed to be more consistent and I still couldn't re-introduce the fault.
I am hoping to glean some useful info from the Bentley manual which should arrive tomorrow.
Thanks for your interest.
Ken