Club 80-90 Forums

Is this possible?
When I put the engine in 12 years ago, I thought I could get it re mapped ( because it has an ECU) to suit pushing a Syncro Westy around instead of a Golf. I have started looking for information about this and cant seem to find anything definitive. I could just do with more torque lower in the rev range. It's OK, but it feels like it could be much better.
 

have you got the ODB2 connector? Standard ECU?

Then the answer is probably yes

Yup, OBD2, standard ECU and immobiliser.
Any idea where I can find relevant info?
Its a from a 1998 Golf 3

Remapping the earlier ECUs isn't that easy, Andy can do it for suitable models and knows what he's on about. Usually though its a case of reducing the low rev torque to protect the transmission as I understand it. TDis are torque monsters by comparison with the engines our vans had originally and for which the transmission was originally built: as I understand it the 1Z/AHU is the revvier engine which suits the transmission best. Low revs does not always equal lower fuel use and lugging is the worst thing you can do with a heavy van. Obviously you are in a hilly area but you don't need to be able to drive as if you were in a 2025 EV just because more of your local traffic is running around in them driving too fast for the roads.

The boost doesn't really kick in til over 3k revs so it feels like I'm giving it beans all the time, shifting at the top of the green range (on the t3 diesel rev counter at least) which is close to 4.5k IIRC.
To be fair, I still haven't fitted the chargecooler so that could make a whole world of difference and I suspect my turbo is no spring chicken so both of those are higher on my priority list but I am just trying to prep everything for when I have sold a couple of vans and have some space and cash to invest. 
On the same note, what is current thinking on DMF for these engines? Searches come up with a mixed bag.

Sounds like the turbo isn't really doing its thing, afaiaa it should start boosting from around 1500rpm and be pretty much full boost by 2000rpm

I believe the JX turbo boost kicks in from around 2000rpm hence most had the 5 speed box in 2wd to help keep the turbo on the boil and reducing lag between gears, but that's the old big slow turbo IDI technology; TDi have smaller faster spinning turbos I think. I may be wrong though, but that was my understanding of how they work. Obviously if you have a hybrid set up then it might be different.

or your rev counter isn't telling the truth about revs ?

I use torque app on my phone with a bluetooth dongle in the OBD port, and I can keep an eye on many things with that. It's ace.
I only just found why I had no feed from the W connection from the alternator, so have been using Torque for revs until recently. It was also useful to calibrate the van rev counter once it was working and it's pretty close now.
The turbo is stock from the AHU but I think perhaps I have a different manifold. Cant quite remember that far back ( I shall see if I mention it in my thread from that time) and it is old. I only discovered recently why I had no boost at all and it was because the wastegate was stuck. It appears to be working now but boost can still drop off to 12psi if I go much over 15 for more than a second or two which I don't think is right (and is a pain up a long hill).
They seem to be adjustable but that's another thing I can find very little info on.

I know there must be plenty of people on here with that kind of knowledge hence various posts but I guess lots of people use faceache these days. I know that was a growing phenomenon before my 8090 wilderness days.

You reference Andy, I'm presuming you mean Syncroandy?
 

hotpod wrote: ↑03 Sep 2025, 13:06
I know there must be plenty of people on here with that kind of knowledge hence various posts but I guess lots of people use faceache these days. I know that was a growing phenomenon before my 8090 wilderness days.

You reference Andy, I'm presuming you mean Syncroandy?
 

There honestly don't seem to be many diesel boys who contribute much, never has been, even when TDi conversions were a thing there wasn't mcuh sharing, it was a few specialists who kept their trade secrets exactly that, and then the bodgers; part of what always put me off them (apart from the nasty tractor engines themselves ) so there's so little real knowledge sharing on the diesel side of things apart from a few JX enthusiasts keeping it original and a few AAZ conversion peeps clinging on - no one really ever updated Thomas's posts from 15 + years ago for example.

Andy = SyncroAndy yes

You need to be on the specialists diesel forums

Thanks Aidan.
My maths back in 2013 was the £2.5k + cost of a 112i rebuild or my mates low mileage golf 3 AHU tdi for £300 
Plus, back in the day I was foolishly trying to get off fossil fuels and it ran happily on used oil biodiesel ( still does but my mate not making much anymore) I do also love how robust it feels and that it is a fairly straightforward fit with all VW parts.
Ooh, and it does 3ish mpg rather than 22 ( and I've not even fitted the chargecooler yet) .

I have been trawling the tdi forums but they are quite sparing with the info on AHU's for some reason. ( they are 30 years old I guess)

Andy is taking a break by the looks of things. I'll not bother him.
 

Helston Diesels were the local geniuses,
things might have changed these days.
Could be worth giving them a call?

There is a possibility, and another possibility on a different path.

My Syncro has an AHU which was transformed to an AFN. The basic engine is the same.
To achieve the 81Kw engine character, you need the Variable Geometry too.
The turbo, the injection pump and the ECU were replaced.

For the turbo, you can use the AFN turbo. You can use the original exhaust manifold, where is some cases an adapter will be  needed. You can source the adapter from Tim at Ultimate Engineering. 

The part number of the pumps are :
AHU: VW 02813110H, Bosch 0460404485.
AFN: VW 028130115A, Bosch 0460404969.
It would be somewhat expensive, or you might find a used unit and have it refurbished.

Finding the correct ECU is fairly easy, and the are so many part numbers. Basically the part number of your current ECU with a different suffix letter or letters.

Oren

Thanks Oren, I shall look into that.

And thanks rollercoaster, I shall give them a buzz and pick their brains. I have been using Richards Bros for the Caddy so I might try them too. I'd not thought of that.