Thin Yellow Pipe Connection

Do we now have evidence of a component associated with the exhaust flap? This might just chuck the ball in the air again & who knows what it’ll land on.

Or do we have an admixture of two systems, that’ll be interesting.

I'm still thinking its the exhaust flap, the link I posted didn't activate (me prob) but if you cut and paste it into google search it will open on the correct MG Obsession page. One of the pictures is a bit dark on my screen so I've attempted to clean it up a bit (below) if this is the bits your looking at it is part of the exhaust flap system.

I will follow this with interest, I asked a similar question a few weeks ago; https://www.the-t-bar.com/forum/9-mgf-tf-pitstop/98598-where-does-this-pipe-plug-in#203067 I did as was suggested and removed the pipe close to the solenoid valve, but since then the TF is a bit gutless between 2000 and 3750 rpm. The connector to plug is on the offside end of the inlet manifold, it's easier to see when the header tank is removed. I used a machine screw that was a tight fit into the short rubber connector on the manifold.

Deepfat - the ultimatemg url is the area described - So it appears that Exhaust Flap Actuator it is.

Journeyman - the only potential place I could find for a connection is at the offside end of the manifold below another vacuum connection - no opening present so I assume has been previously blocked off.

My thanks to all - I'll remove the redundant parts to avoid confusion in the future.

JR I would look at MGB's post first, the MG Obsession link says removal wont upset the ECU but I have seen a couple of posts saying it does upset the ECU when I did mine I just stopped the pipe up at the back box end just in case.
We really need an expert on the ECU's inner workings to say one way or another and that sure as hell is not me, when I hear "ECU" I also hear my Mum saying "the bogeyman will get you"
In your position I would make sure the manifold connection is stopped up then maybe disconnect the electrical plugs and secure them out of harms way but leave the hardware in place, if everything is fine and you have no probs you can remove it later.

Whilst I can’t say for sure, I can’t see it would make much difference to the ECU.
I doubt it provides an input to the ECU, it would be an output from the ECU that controls it.
Why would the ECU need to know whether it is open or closed when it is what tells the vacuum unit when to open or close…it should already know!
I’ve had a squiz at the TF workshop manual which like most manuals these days is an appalling piece of technical writing, all over the place like a mad woman’s shit and as far as I can see there is precious little on the subject, however looking at the wiring diagram there are 2 wires….one the brown/pink will be the power feed the other blue/black goes back to the ECU, this wire will control the vacuum unit.
There would be at least a third wire if the ECU required feedback, so as it doesn’t have anymore than two wires the ECU should be unaffected by disconnection.

Cobber says: There would be at least a third wire if the ECU required feedback, so as it doesn’t have anymore than two wires the ECU should be unaffected by disconnection.

Whilst I do not claim to be an expert on ECUs, I know that the F & TF ECUs are able to detect when a seat-belt pretensioner is disconnected, or has connector contacts so dirty that they provide high resistance. It can do this by detecting that a low voltage (far too small to fire the pretensioner!) generates a small current through that circuit. More modern ECUs on most modern cars detect "bulb failure".
There is no forest of extra wires going out to every transducer, bulb and solenoid to provide "Feedback". The ECU is able to "see" if it is sending signals out to (roughly) the resistance it is expecting on each circuit, then generate failure codes and/or warning light signals accordingly.

IMO, Roger Parker (in MGF and TF Restoration Manual) is correct on this one, see:
https://www.the-t-bar.com/forum/9-mgf-tf-pitstop/98648-thin-yellow-pipe-connection?start=0#203629

Okey dokey. Thanks

The easiest way to see whether a device is still functioning in a network is to monitor current flowing through a resistance, low enough in value not to impair the system function but high enough to create a voltage drop, this can be monitored. Hence a two wire system can provide its own feedback.
I’m no longer a member of the MEMS3 fraternity & as this is where this system lives I can only speculate. It’s “useful life span” was only a few years, it was either poorly received or too costly to implement, whichever there should still be an imprint in software that might be read by a T4 (a Pscan might not have these facilities programmed in).
If we take MGB281 problem for instance: if he was to take his car to an MG Rover garage complaining of his problem, the first thing they would do is connect up the T4 & if there was a problem in this network it would be flagged up & the technician would change that network whether it needed it or not, test again then throw the car back out into the big wild world.
Pektron won’t have redesigned the ECU it will already have had spare ways engineered into the unit to be enabled in software.
If that fault code signature is imprinted in software it can be traced but I bet you’ll need a T4 to find it.
There is value in both sides of the discussion, however to resolve it to everyone’s satisfaction you would need a car with the system still fitted but not necessarily plumbed through to the actuator & one where everything had been stripped out & the manifold plugged add to this a T4 in the hands of an expert. With this a definitive answer would be found.
M

Airportable's logic is flawless. I can offer a 2002 TF with (to use his words) " a car with the system still fitted". MGB281 appears to have a car "where everything had been stripped out". IF MGB281 also has the Solenoid, and can plug it back in to the wiring, we just need someone in the Taunton or wider Somerset Devon area with a T4 and the appropriate knowledge. Any offers?? Martin Smith????

Never having seen one of these stupid things on a TF, I’m assuming the two wires go to a solenoid that opens and closes a valve on the vacuum unit that goes on to open and closes the exhaust flap, it this is so what possible useful feedback could the solenoid offer the ECU? The solenoid will either be activated or not, the ECU should know that it has activated it.
If however those wires go to a servo motor then maybe some feedback might be of use, I doubt this as both wires don’t go directly to the ECU, the brown/pink wire also connects to a circuit that includes injectors, ignition coils, O2 sensor, etc. Too may things to reliably measure circuit resistance.

But I am limited to what I could glean from the manual.
Like I said the manual is a poor technical document, unfortunately these days they are mostly written by junior engineers just out of school, not anyone who has a clue.
Once I managed to convinced the powers that be, that the technical manual for their expensive machine was best used as a doorstop, I was asked if I thought I could do better, I told them I could and then was given the task of rewriting the damned thing so as someone can actually use it as a guide.
It’s amazing the difference that an explanation of what every thing does and how it effects others components, clear hi definition colour pix, tables of desired values and specifications, diagnostic procedures, flat finding tables, clear step by step instructions, provided in a logical sequential order and using consistent terminology, makes to some poor bastard who has to read it