80 TDi Couple of probs/questions

[adamss24]

Thats is the variable vane mechanism (the moving fins inside a Garrett turbocharger) and with carbon build up it jams and may set a code in the memory. If your turbocharger is wastegated(KKK) then you may disregard this thread as its operates differently and if faulty you should check for a stuck open/close wastegate that will trigger a overboost/no boost code and one should check the vacuum hoses for splits and cracks leading to similar symptoms. Generally KKK turbochargers are a bit more reliable but the Garret ones are more common and easyer to tune and much cheaper...!

[Marc97]

Cheers, my car has an actuator on the turbo so I guess that means its a KKK?
I have checked all vaccum pipes but they are all fine, I'll have a play with the actuator/wastegate and clean the wastegate hinge tommorow.
Will the overboost code remain on the ecu and stay as a fault?
Will it affect the car until it gets cleared?
Can I clear it by disconnecting the battery lol??? (well it is an old car, it might not have the same memory capacity as all the spritely younger cars )

Cheers Adam,

Marc.

[adamss24]

Cheers, my car has an actuator on the turbo so I guess that means its a KKK?
I have checked all vaccum pipes but they are all fine, I'll have a play with the actuator/wastegate and clean the wastegate hinge tommorow.
Will the overboost code remain on the ecu and stay as a fault?
Will it affect the car until it gets cleared?
Can I clear it by disconnecting the battery lol??? (well it is an old car, it might not have the same memory capacity as all the spritely younger cars )

Cheers Adam,

Marc.

They will stay logged in the memory until you disconect the memory. Newers models logs them onto a non volatile memory that will hold for a while(dont know how long). Turbo related faults will/may trigger Limp Mode and will clear as soon as you stop/start the engine again until the condition that make it reocurs.

[Marc97]

So I can clear it by leaving the battery off for a couple of hours then.....WOOHOO.

mate.

[pcar964]

Marc,

Our 80 TDi Audis do not have the variable vane technology turbos, our 90bhp engines have standard wastegate turbos.

Where did you read that it's a fly by wire throttle? I've driven a few of these like the V10 M5 and 996 & 997 Turbos and not found it to be a "weird feeling"


Adam,

I've driven many cars, diesels and petrol, turbos and nasp. Nothing has ever been intermitently so lacking in power when pulling away, so it's a fault, not my driving style.

Wish I had a code reader

Peter

[Marc97]

Where did you read that it's a fly by wire throttle?

My car doesn't have a throttle cable so I'm guessing it is a 'drive by wire' system.

PS, still not fixed!!!!

[Ally80]

Hi Mark,I,(new member Ally80)found ,while surfing the net for answers ,that you are experiencing the same problems as myself regarding the strange behaviour of the engine management system on your audi 80 1.9 Tdi.I do know that it has nothing to do with the way your driving the vehicle.I've had my TDi estate for 6 years(done 130k)and now the thing's acting up with high revs between gear changes and some times no acceleration when pulling away at a junctions/roundabouts!! most annoying.I think that it could be the accelerator pedal sender/throttle position sensor acting up,not sending the proper signals,though not sure.If you do hear anything or find a remedy please let me know.
I was quoted £409+vat from Audi for this part, so I won't be buying one as part of my ilimination process.

Regards

Ally

[pcar964]

Hi Ally,

Welcome to the group. Price of the throttle sensor is exhorbitant. Until Marc pointed out it was a fly by wire throttle, I hadn't known. With the injection pump being under a plastic cover I hadn't noticed the absence of a throttle cable - doh. Learn something new every day.

I have vag-com 409.1 and Audi-VWTool Version2.0.9.exe to read, reset and programme the ECU, what I don't have is a data cable to connect PC to the OBD connector.

If you or anyone else were able to lend me a cable or suggest where I can buy one cheap, or how to make one I will try and figure out what causes the problem.

Peter

[adamss24]

Hi Ally,

Welcome to the group. Price of the throttle sensor is exhorbitant. Until Marc pointed out it was a fly by wire throttle, I hadn't known. With the injection pump being under a plastic cover I hadn't noticed the absence of a throttle cable - doh. Learn something new every day.

I have vag-com 409.1 and Audi-VWTool Version2.0.9.exe to read, reset and programme the ECU, what I don't have is a data cable to connect PC to the OBD connector.

If you or anyone else were able to lend me a cable or suggest where I can buy one cheap, or how to make one I will try and figure out what causes the problem.

Peter

See ebay for cheap cables and forget about making your one as it will be hard work to debug the interface. See rosstech for how to resync your accelerator position sender with the ecu(diesel pump) and see if its changes into better. See tdi forum for more details. Do a search there using thee boolean search as usually the other one is not that accurate ! Remember that its not as good as the google search engine and dont give up, read trough the posts as its a interesting forum and yankees are quite happy to share info ! Good luck.

[pcar964]

Adam,

You mean the forum at this site? http://tdiclub.com/

Been reading the faqs, sounds complex.

Found this cable on ebay, price is not too bad, but I'm a little way of dealing with a seller in China. If it doesn't work doubt I can get a refund.

What do you mean by hard work to debug the interface? Is't it just a cable with an 16 pin OBD-II connector on one end and an 9 pin serial on the other? Then all I need to know is which pins to connect. I make my own scart cables (proper ones using all pins) and network cables.

Was working on a Porsche 997 Turbo Tip earlier today, very nice, very fast

Peter