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Sensor Problem I guess, car suddenly runs lumpy and black smoke out of exhaust. Switch off the ignition leave for a few minutes, start it back up and its gone !
Anyone had this problem, ideas to what causes this ?
Sensor Problem I guess, car suddenly runs lumpy and black smoke out of exhaust. Switch off the ignition leave for a few minutes, start it back up and its gone ! Anyone had this problem, ideas to what causes this ?
If we are to be more helpful, you need to tell us whether your engine is a 3B or ABY or ADU (your avatar seems to show an RS2 (ADU) but I think you have a coupe).
As in your other (O2 sensor) thread, the problem could be your G62:
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RS2'd 93 UrS4 5 spd sedan
94 UrS4 V8 6 spd manual avant
Sorry its on the 3b, thanks for the attachment. Can i test this using a multimeter measuring resistence ?
Allow the engine to cool to room temp (68F/20C)
Disconnect ECT sensor from harness connector
Switch multimeter to resistance range
Connect multimeter to terminals 1 and 2 of the ECT
Resistance must be 1500 to 3000 ohms
RS2'd 93 UrS4 5 spd sedan
94 UrS4 V8 6 spd manual avant
...after changing the MFTS last night the problem went away. Until this morning, drove to work and just as i arrived it started again. Black smoke over fueling.
Last night after changing the MFTS the temp gauge in the car read a higher temp, engine was warm reading nearly 50 deg on the old sensor and 70 deg on the new one.
I changed the G62 first but no change, old unit read 2970 ohms. Wondering if this is a loose wire / faulty connection. Also doesn't the 3b use both sensors, aby/adu uses just the G62?
How do i read this value from the ecu and where do i get vag.com and hardware etc (is there a hand held unit available ?)
Check the condition of the maf, maf plug and connectors - Newsh had loads of problems with it and it could cause an overfuel of the car due to bad reading. Unlikely to cause an intermittent faultt like this but still, worth a look.
Cheers'en, AndyC
1994 ABY Coupe - Projekt Alpinweiss
I changed the G62 first but no change, old unit read 2970 ohms. Wondering if this is a loose wire / faulty connection. Also doesn't the 3b use both sensors, aby/adu uses just the G62? How do i read this value from the ecu and where do i get vag.com and hardware etc (is there a hand held unit available ?)
IF you have automatic climate control, Channel 51 has a coolant temp. reading (a third sensor, not the G62, not the MFTS) that you can access to get a real temp.)
Here is info for the C4 chassis that should cross to a B3 S2 (with automatic climate control):
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RS2'd 93 UrS4 5 spd sedan
94 UrS4 V8 6 spd manual avant
Sorry i haven't got automatic climate control.
I'm now thinking is the wire / plug to the MFTS, got hold of this unplugged replugged giving the wire a wiggle and the car started to correctly straight away.
Really need to know how to get the temp reading from ecu ???
Sorry i haven't got automatic climate control. I'm now thinking is the wire / plug to the MFTS, got hold of this unplugged replugged giving the wire a wiggle and the car started to correctly straight away. Really need to know how to get the temp reading from ecu ???
Too bad about no AutoClimate control. All I can offer now is this link to MFTS info, including pin-outs and PNs for replacement plugs and a 3B pin-out (I think the MFTS signal is pin no. 36 because 45 is the G62). Reading either would likely require a VAG-com connected to the diagnostic ports in the fuse box.
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RS2'd 93 UrS4 5 spd sedan
94 UrS4 V8 6 spd manual avant
Ian, check the multi plugs on the firewall to make sure they're not wet/dirty. Also the ECU grounds on the inlet manifold near the dizzy, give them a tug to make sure they're not held together by corrosion
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...after changing the MFTS last night the problem went away. Until this morning, drove to work and just as i arrived it started again. Black smoke over fueling. 
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