EllisoJo

First off: Congratulations on getting your TF back OTR. I was going to ask, just before you started this thread, but the thread tells the story pretty completely.

On the "Thin Yellow Pipe" thread, you said that you have left the exhaust flap control solenoid connected ELECTRICALLY, as I understand it. If so, that bit of the ECU functionality does not explain the flat spot on this thread.

Apparently, the ECU learns an engine set-up, and can take many miles of driving to achieve an optimum setting. Perhaps that explains your comment (from the "Thin Yellow Pipe" thread: "...........sluggish performance between 2000 and 3750 rpm which is still there although not as bad as it was. I have not had any feedback from the forums but will contact K Maps to see if they have any idea where the problem may lay.


K maps undoubtedly know more about the ECU than either of us, so their advice if replacement of the Lamda sensor does not work will be invaluable.

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????

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

Deepfat is (as always!) correct. I have posted a reply with pictures on the The MGF Register Forums site (where I saw your request first). The two bottom "Spires" as Deepfat calls them had no fasteners on at all on my TF, but they DID still prevent the cover being removed, until the cover was gently prise over these studs. Be gentle with this plastic, as it is probably more than 20 yrs old, and less flexible than it was.

Roger Parker (who knows a thing or two about Fs & TFs) says: "When fitting a new exhaust to a car originally fitted with an exhaust valve, it is important to leave the electrical connections to the exhaust control valve, otherwise the engine ECU can throw up a fault". The "exhaust control valve" is the part in your first picture.

It is possible your car has a modified or re-programmed ECU, but if that exhaust control valve was connected to the wiring loom when you first started working on the car, I would advise taking Saint Roger's advice and re-connect it electrically, but leave the pneumatics unconnected.

Re. Water in the gearbox oil: I would not disagree with any of the comments above. For what it is worth, given that you have already removed the subframe & Engine/gearbox assembly, it surely makes sense to split the gearbox from the engine, so that the clutch can be checked and (probably) replaced, unless you know that this job has been done.
I have read elsewhere that clutch release arms are prone to rusting and seizing. Given that your car was "Baptised", the chances that your clutch release arm has NOT started to corrode badly seems vanishingly small. I believe Mike Satur does an improved release arm with a grease nipple.
Once you have the gearbox out, you can look for signs of corrosion, and do at least a partial strip. There is good advice (3 pages with 7 photos) on this subject in Roger Parker's "MGF and TF Restoration Manual" The key point is that there is a circlip which MUST be removed before the main case can be lifted off. Once you have removed that, checking for corrosion should be easy and you will certainly be able to eliminate any remaining water and muck before a re-fill.
I have to say that I admire your determination to get that car refurbished! Hard to see it as an economically viable project, but I guess that is not the point!
Good Luck!

John in Devon wrote:

Thanks, Ellisojo. I do have a low coolant alarm - agree that it does give peace of mind - even on short journeys in heavy traffic.

So, you suspect the sensor/gauge may be faulty? Where is the sensor for the temp gauge situated, please?

Hopefully, below is a picture of my engine bay, with the ECU sensor circled in red. The sensor for the water temp gauge is below, and extremely difficult to reach with engine in the car!


I have tried to insert a picture from MG-Rover site (Credit to "CJJ") with engine out which might help explain locations better.