You can change the style the forum displays by selecting your preferred style at the bottom left of the site.
We have made an enhancement so that old threads should now link from search results to the correct thread. This is not yet in place for single post links
I will give the disconnecting electrically it a go. What should I be looking for when I disconnect it? The car is already acting like it's only working of the spring pressure only.
Probably because your N75 is not connected to the ECU or the ECU is not getting a properly boost pressure signal to the internal MAP sensor.
If MFTS circuit is causing a false over temp signal, ECU will cut boost to wastegate pressure as it thinks the engine is overheating. Disconnect the MFTS to prevent it.
Other than MFTS AFAIK the only other reason the ECU will cut boost to WG pressure will be a knock sensor fault, this should throw a code. Otherwise you problem is mechanical I.e. N75 or MAP sensor wiring or plumbing issue
Panthero Coupé quattro 20vt
Indigo ABY coupé
Imola B6 S4 Avant
If MFTS circuit is causing a false over temp signal, ECU will cut boost to wastegate pressure as it thinks the engine is overheating. Disconnect the MFTS to prevent it.
Other than MFTS AFAIK the only other reason the ECU will cut boost to WG pressure will be a knock sensor fault, this should throw a code. Otherwise you problem is mechanical I.e. N75 or MAP sensor wiring or plumbing issue
I had a problem with the MFTS plug. I changed the plug but I wonder if the wires were damaged.
I'm of from the 24th til the 5th. So that should give me plenty time to check everything that's has been suggested.
So I just took the MFTS plug of and went a drive on my lunch break. The car is now boosting to 0.9 bar and is a lot quicker. So I'm still at full boost but the plug seems to be one of the problems!
So I've just ordered some terminals from here:
Surely the Homefries ecu should be nearer 1.4 bar. The stock ecu being in the 1.1 bar region.
So whilst there has been an improvement you are still not getting full boost by the sound of it.
It might actualy be the MFTS that is faulty as disconnecting the connector means the ecu does not see the signal and therefore does not limit boost. So if it limits boost connected and doesen't when disconnected that sort of implies the MFTS.
Not sure what combination of bits you have used to reassemble the wastegate but that might need a bit of investigation! With a stock spring and preload I think it should be nearer 0.4bar mechanical with the WGFV disconnected. You seem to be a bit higher.
Surely the Homefries ecu should be nearer 1.4 bar. The stock ecu being in the 1.1 bar region.
So whilst there has been an improvement you are still not getting full boost by the sound of it.
It might actualy be the MFTS that is faulty as disconnecting the connector means the ecu does not see the signal and therefore does not limit boost. So if it limits boost connected and doesen't when disconnected that sort of implies the MFTS.
Not sure what combination of bits you have used to reassemble the wastegate but that might need a bit of investigation! With a stock spring and preload I think it should be nearer 0.4bar mechanical with the WGFV disconnected. You seem to be a bit higher.
I have just tried with the MFTS and WGFV disconnected and it is only boosting to 0.4 bar which will be spring pressure. I will focus on the MFTS just now. Then see if i can find any other problems and hopefully i can find the extra boost to bring it up to 1.4 bar.
Sounds like you have a combination of issues. Check the boost line to the ECU for damage or cracks, and boost leak check. If that doesn't solve it I would look at the N75
Panthero Coupé quattro 20vt
Indigo ABY coupé
Imola B6 S4 Avant
Are you 100% sure it has a Homefries? The reason I ask is that wastegate mod would not be necessary on what we refer to as Homefries.
Its a shame you haven't spent some £ on a better method of fault code reading. Even an old Vag com would gives you some more info that might be useful other than just codes. For example you wouldn't get full boost without the ecu seing a certain full throttle value which is easily observerable with Vag com/VCDS. Again the reason I mention this is because you have had a TB issue previously. Perhaps you know someone locally who might be able to plug theirs in just to check a few things.
I went for the kit with the updated jhm collar instead of the OEM collar.
Thanks for answering.
I was a bit confused that JHM specifies only transmissions from B5 with which I'm not familiar but then I thought 01E is 01E and now I see that this kit should fit as well transmission from diesel Audi C4, for example code DQT
Are you 100% sure it has a Homefries? The reason I ask is that wastegate mod would not be necessary on what we refer to as Homefries.
Its a shame you haven't spent some £ on a better method of fault code reading. Even an old Vag com would gives you some more info that might be useful other than just codes. For example you wouldn't get full boost without the ecu seing a certain full throttle value which is easily observerable with Vag com/VCDS. Again the reason I mention this is because you have had a TB issue previously. Perhaps you know someone locally who might be able to plug theirs in just to check a few things.
Can't say for sure if the car is a homefries. It was advertised as having a homefries chip in it when sold to me.
As for the fault code reading. This car was sold to me as one of the better example about at the time. So to me a basic code reader was all i was going to need. If i knew what i did now back then i would have invested in vag com or something better. I would probably go as far a saying i would have saved myself ££££'s and not have bought the car in the first place. I am hopefully getting to the end of the problems with the car so i can start enjoying it!
Thanks for answering.
I was a bit confused that JHM specifies only transmissions from B5 with which I'm not familiar but then I thought 01E is 01E and now I see that this kit should fit as well transmission from diesel Audi C4, for example code DQT
Yeah, i thought the same when i first looked at the site to buy my kit!
So I just took the MFTS plug of and went a drive on my lunch break. The car is now boosting to 0.9 bar and is a lot quicker. So I'm still at full boost but the plug seems to be one of the problems!
So I've just ordered some terminals from here:
Just suggestin............As you're doing the MFTS wiring, consider ordering a new 'brown' oem MFTS plug from the dealer, that connects to the MFTS sensor. A new plug is lovely, compared to a crumbly original. Relatively inexpensive.
Following your trials and tribulations as you make progress. Hopefully you're nearing the end soon. When they go right they are addictive. When not, you feel like touching them when you can't work out what the problem is.
Hindsight is wonderful, but all cars tend to have issues. Once you get it all sorted, make sure you keep it for ages to full enjoy the benefit from all your grief, stress, hard work and expenditure.
Thanks for sharing all of the various issues for the rest of us to learn from.
Last edited by macspring; 21 December 2015, 14:33.
Just suggestin............As you're doing the MFTS wiring, consider ordering a new 'brown' oem MFTS plug from the dealer, that connects to the MFTS sensor. A new plug is lovely, compared to a crumbly original. Relatively inexpensive.
F76 Multifunction Temperature Switch R&R Info including PNs for the plug and pins and pin-out complete the picture:
We process personal data about users of our site, through the use of cookies and other technologies, to deliver our services, personalize advertising, and to analyze site activity. We may share certain information about our users with our advertising and analytics partners. For additional details, refer to our Privacy Policy.
By clicking "I AGREE" below, you agree to our Privacy Policy and our personal data processing and cookie practices as described therein. You also acknowledge that this forum may be hosted outside your country and you consent to the collection, storage, and processing of your data in the country where this forum is hosted.
Tweet
Comment