The SA 2.6i Microbus thread

for questions and answers about alternative power transplants on the T25, GTi, Porsche,Subaru etc, this is the place. You must register to post but anyone can read.

Moderators: User administrators, Moderators

Post Reply
silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

The SA 2.6i Microbus thread

Post by silverbullet »

I appreciate that this is pretty obscure but here goes...broke down in the 2.6 SA on Friday, had to be recovered :oops: thought I had fixed it with a new coil over the weekend so used it Monday ok and then this morning it ran for all of 10 seconds then died and wouldn't restart.
Symptoms are:
Sudden failure to start after a 75 mile journey; would eventually start but die if more than 1200 rpm; could pull away and drive but would soon stall again; restarted after standing 2 hours (stalled once but restarted again to turn round for loading onto recovery truck)
The ignition is a Hall-effect trigger (I think) type Bosch dizzy, the coil is a non-TCI generic VW modern "block" type (loom has a slight mod to remove multi-plug, it has 2 terminal posts instead like a Golf or Passat). Ignition was modded/repaired soon after import in c.2005 by a SA ex-pat mechanic in the Basingstoke area.
It also has what is described by etka as an "altitude sensor" on the bulkhead, with a vacum hose to the inlet manifold and a multiplug (3 pin) Not sure if it should have a TCI or not, etka not clear but it's run ok for the last 6 years as it stands.
Where to start? Suspect the trigger in the dizzy? Trying not to tear my hair out but it is my daily driver and everything else is broken, apart from the Mrs' trusty Sharan...
Help please!
Last edited by silverbullet on 14 Jan 2012, 15:30, edited 3 times in total.

User avatar
Aidan
Trader
Posts: 6641
Joined: 11 Oct 2005, 19:21
80-90 Mem No: 742
Location: Llanfyllin, mid Wales : )
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by Aidan »

looking at ETOS hall sender is on end of camshaft not in disi, disi looks simple. Do you have an ignition amplifier module on yours - switch unit TCI -17S 905 351 B or suffix A - the equivilent on our systems are often the culprit in situations like this

User avatar
bigherb
Registered user
Posts: 2580
Joined: 27 Mar 2008, 13:50
80-90 Mem No: 5789
Location: West Kent

Re: Ignition/starting fault on SA - one for the experts

Post by bigherb »

First you need to establish what you are losing, spark or fuel! First when the engine wont start remove the HT coil lead out of the distributor hold it close to an earth point and crank the engine to see if you have a spark, it's easier and more accurate if you get one of these just insert it between the spark plug and HT lead it flashes when there is a spark. Halfords used to sell them as well.
http://cgi.ebay.co.uk/Spark-Plug-HT-tes ... 4aa9796198" onclick="window.open(this.href);return false;
1982 Camper 1970 1500 Beetle Various Skoda's, Ariel Arrow

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

Aidan wrote:looking at ETOS hall sender is on end of camshaft not in disi, disi looks simple. Do you have an ignition amplifier module on yours - switch unit TCI -17S 905 351 B or suffix A - the equivilent on our systems are often the culprit in situations like this
AIdan - I looked at that particular etka diagram (if it's the one I think you mean) and it shows the V6 engine :roll: There's nothing on the end of R5 head apart from the dizzy poking out towards the centre of the engine bay, behind the last/first spark plug.
It doesn't have a TCI but since it's been modified it may not have the correct dizzy either, in which case things get a lot worse from here. It has either an optical or Hall sender inside.
Time for a picture or 3 and some part numbers - more later.

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

Here you go:
The general arrangement, the "altitude compensator" is to the far right of the coil (cruise relay and diagnostic socket in between) and the 3 wires from the distributor join the loom and head in the direction of the ECU, under the rear bench. Maybe these have mapped ignition, hence no TCI?
Note: old picture with suspect coil fitted, replacement identical.
Image
Bosch distrubutor part number
Image
Inside the distributor:
Image
Last edited by silverbullet on 24 Mar 2011, 20:46, edited 1 time in total.

User avatar
bigherb
Registered user
Posts: 2580
Joined: 27 Mar 2008, 13:50
80-90 Mem No: 5789
Location: West Kent

Re: Ignition/starting fault on SA - one for the experts

Post by bigherb »

Looks like the standard setup, the TCI is built into the coil.
1982 Camper 1970 1500 Beetle Various Skoda's, Ariel Arrow

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

This coil does not have a TCI module, it's just a basic dry coil. I should know, I fitted the replacement! SA's are nothing like German-built vans. The EMS doesn't even use a MAF sensor for a kick-off, so it's not like any EFI WBX at all.

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

Image
After trawling a LOT of online lists and cross-referencing to double check, I have found out that the mystery module top right is a MAP sensor - for a 92-95 Audi 80 1.9TD 1Z !!! This is how the engine senses load. Distributor is generic VAG recon from the Bosch part number 0 986 237 678 (0 237 522 015).
Managed to source both from trade suppliers on £bay for less than the cost of the dizzy alone via LMF...
Trying hard not to think about the 22S Motronic ecu...to awful to contemplate if it's getting twitchy.

And yes that CV boot has had it :oops:
Last edited by silverbullet on 21 Apr 2011, 22:14, edited 1 time in total.

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

Well it wasn't the MAP sensor at fault and the dizzy that came has the wrong trigger unit (meant for a TCI, and this one isn't)
Back to google with the part number of the Bosch trigger unit now...should have known better than buying a generic part off £bay :roll:
Hall sensor in the Bosch has part # 1 230 329 038 but I can't find it online...

User avatar
Aidan
Trader
Posts: 6641
Joined: 11 Oct 2005, 19:21
80-90 Mem No: 742
Location: Llanfyllin, mid Wales : )
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by Aidan »

according to etka your original disi 034 905 205H obsolete replaced by 034 905 237 AX which is £85.43 plus vat from VW - it might be worth checking - I think the Hall Sender shown as on the end of the 6 pot is what is in your unique disi, found one other link in Etka for that disi 1986 Passat engine code SK which doesn't show anywhere else, so it could be a mistake in Etka/Etos
the original coil was unique though that new coil pack -ignition transformer is fairly widely used now
no info on the rest of the engine management bits - iluus 906-10 only gives the ecu info none of the other parts like the MAP sensor in version 7 or ETOS which shows the full picture but no detail
nightmare

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

Yup, it's a nightmare alright...but I got an email from syncrohospital this morning :D and Stuart hade the same symptoms with a 2.6i syncro :shock: back in December. TPS pot was the culprit, they opened it up and improved the brush tension on the contacts as a spare wasn't available and it's been ok ever since.
So that's what I'll try today and get it re-timed. Somehow.
That illustration in etka is definitely wrong (but the part numbers might be correct) :evil:
I have just bought a manual for the later Audi 80 that includes 2.3 and 20v engines so should tell me most of what I need...

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

Here's the TPS, with a nice friendly German VAG part number (Golf Mk 3)
Image
With the aid of a punch to pop out the rivet tubes and some matchsticks to lift the snap tags (broke one off, whoops) I find this inside:
Image
The matchstick is pointing to a part of the carbon track that corresponds to about 1/3 throttle, and the white ceramic of the backing is showing through...I tweaked up the contact fingers about 0.5-1mm as the pressure was non-existant, but it runs just the same.
Time for a new throttle pot.

User avatar
Aidan
Trader
Posts: 6641
Joined: 11 Oct 2005, 19:21
80-90 Mem No: 742
Location: Llanfyllin, mid Wales : )
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by Aidan »

I said it was just like no afm on a digifant symptom, is the golf one still available ?

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

Looks like it's still available as it also fits other models - Stuart tells me he can get them in SA too but they are a bit dear. I'll try TPS first thing Tuesday before sending a shopping list to Pretoria...

silverbullet
Trader
Posts: 16537
Joined: 08 Jun 2009, 09:51
80-90 Mem No: 6908
Location: Surrey Syncronaut #156
Contact:

Re: Ignition/starting fault on SA - one for the experts

Post by silverbullet »

044 907 385A is still a good part number at VW :D and it's a whisker over £50 + vat :?
The bus has got to have one, so if this fixes the fault I'd better have a spare before they go NLA...

From my conversations with stuart at syncrohospital, it turns out there a early (mine) and later engine management systems for the 2.6i, both unique to SA. They are more advanced that I realized as all the ignition is handled by the ECU (the TCI is built-in) and the distributor is only there to put the spark to the relevant cylinder i.e. it has mapped ignition curves.
The use of a MAP sensor over a MAF means no flow restrictions so better ultimate power output, important at higher altitudes in SA when thinner air means big losses in performance.

Post Reply