mfts symptoms?

[andyg plym]

as you all know my car is bein a proper pain at the moment. Today i finised work and drove home, all of a sudden i had BOOST!!!
Still stuttering but at least trying. Ive noticed temp display is starting to be intermitant and wonder if mfts needs replacing?
Ive replaced these before but never had NO boost.
im still plannin to return the car back to stock manifold setup as the tubular doesnt seem to work on a stock k24
i wonder if a worn out mfts will cut all boost completely? not just a bit, but all of it.

[FITZY]

Mine failed back end of last year, thought my WGFV had failed as went back to mechanical boost only, replaced WGFV - still the same so dis-connected MFTS and instantly regained boost but obviously lost temp gauge op.
If you're in any doubt just dis-connect it and see what happens, should rule it out for you one way or another

[andyg plym]

did you ave any boost at all?

[FITZY]

Yes, I did (but only just) If you have your car running and give the throttle a quick 'blip' by the cable whilst under the bonnet, do you hear your WGFV clicking?

[andyg plym]

yes clicks like its avin a fit

[FITZY]

Wouldn't have thought it was a faulty MFTS then, although like I found on mine, disconnecting it proved the point. Probably a silly question, but are all the hoses in the correct orientation on the WGFV itself?

[UrS4boy]

Andy: If your car is a 3B, the MFTS is connected to the ECU, if it is a ABY it is not, as noted here:

http://forums.audiworld.com/s4s6/msgs/148742.phtml

If you have the automatic climate control, it is possible to check the MFTS output to the coolant temp gauge against the coolant temp going to the heater by using Channel 51 of the climate control as described here:

http://forums.audiworld.com/s4s6/msgs/163785.phtml

Good luck.

[andyg plym]

yes are all fine, can a faulty mfts be knackered but still work temp display?

[andyg plym]

Andy: If your car is a 3B, the MFTS is connected to the ECU, if it is a ABY it is not, as noted here:

http://forums.audiworld.com/s4s6/msgs/148742.phtml

If you have the automatic climate control, it is possible to check the MFTS output to the coolant temp gauge against the coolant temp going to the heater by using Channel 51 of the climate control as described here:

http://forums.audiworld.com/s4s6/msgs/163785.phtml

Good luck.

yes its aby but maybe coincidense wiv boost issues and display intermitant

[FITZY]

yes are all fine, can a faulty mfts be knackered but still work temp display?

My temp gauge was still working fine Thats why I replaced my WGFV first because I presumed the MFTS was ok.

[Paulgo]

When my MTFS was faulty it was retarding boost - but only by about 3-4 psi. It took me ages to identify the MTFS as the cuplrit. In the end I only realised because the temp warning light came on and stayed on (even tho the temp gauge was reading as normal) indicating the MFTS was borked, even though it must have been on its way out for months. They must be able to have an effect on boost even when they havnt failed competely and as a result thats hard to spot.

Try the good old tap trick which worked for me - give the MTFS a few light taps and see if it makes a difference. It did for me, albeit very temporarily when boost went fleetingly back to normal, but at least I finally knew what was keeping my boost levels down!

Paul

[AUDIS2avant]

again MFTS??? blue 4 pin sensor or?

[AUDIS2avant]

I cant erase the above post so here i will ask again, mine is an aby and is down a little on boost and mpg so if its not the mfts sensor that controls this is it the 2pin on the back of head then?

[A80Avant]

can MFTS cause a boost drop linearly at about 0.3bar on all rev range without any signs of problems when driving etc?

[driftin jo]

Andy: If your car is a 3B, the MFTS is connected to the ECU, if it is a ABY it is not, as noted here:

http://forums.audiworld.com/s4s6/msgs/148742.phtml

If you have the automatic climate control, it is possible to check the MFTS output to the coolant temp gauge against the coolant temp going to the heater by using Channel 51 of the climate control as described here:

http://forums.audiworld.com/s4s6/msgs/163785.phtml

Good luck.

This link says nothing about the ABY just about the AAN ! As it happens this is one of the only things the the ABY/AAN differs on on ecu pinout.
The aby ECU is connected to the MFTS so it is possable that it could affect boost.

ref. http://s2central.net/motronic_pinout_ABY.html