MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Bang into the engine when hot...

Hi,

just to give you a little feedback from a problem I've had on my MGF MPi. (from 1996).

There was a problem in fuel regulation when the car was hot. Few "bangs" from the engine (not from the exhaust) and the reason was.... the ECM (Engine Control Module) which failed to regulate the "advance progressivity". In fact, there is a little depression membrane INSIDE the ECM which has a little hole. And I had to completely change my ECM instead of only changing that membrane ;-( Grrrrrr !!
Arnaud

I guess this is the MAP (Manifold Absolute Pressure) sensor that is integral to the MEMS unit on the MPi (but not the VVC).
If yes, then I believe this would not be repaired by an MGR dealer - MEMS must be replaced.
Sorry to hear this - I hope the problems are fully resolved now - sounds like a good diagnosis of the problem.
Steve

You're right, with the correct words it's better ;-)

the MAP which is inside the MEMS is the fault part.
And MGR dealers don't have that part, I must replace the entire MEMS ;-( ;-( ;-( ;-( (for your information, cost here in france : 365 Euros, including VAT)
Arnaud

Hi Arnaud,
these sensors can be bought at the bigger electronic suppliers. Motorola types MPX will fit. I dont have the MPI so dont know the exact numbers after "MPX".
Take a look at the top of the plastic part with the small inlet pipe after opening up the MEMS. Any numbers ? Price for that series of sensors "over the counter" incl. taxes is around 18 to 36 Euros....... No problem to unscrew the 2 bolts and solder the tags.

BR, Carl.
Carl Blom

AAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRGGGGGGGHHHHHHHHHHHHHHHHHHHHHHHHHHH !!!!!!!!!!!!!!!!!

Thanks Carl for your information... BUT you're too late !! I've already ordered a new MEMS for Rover !!!!!!!!!!!!!!!!! ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-( ;-(

I'll kill them !!!!!! (And also, I've had MANY problems with our local Rover dealer. They're not honest here !!! I've asked them to connect my car to their testbook and give me the status and error code : they told me "no, we'll remove your engine, open it and check directly inside, testbook is no use for your problem". But a little garage, after 2 hours of checking, told me that the MEMS is wrong... no need to remove everything !)
Arnaud

>>You're right, with the correct words it's better<<

Arnaud, seeing the price it really doesn't look much better to me. Let's hope it fixes the problem.

JohnP

To avoid this in the future I think you have to do a small alteration to the inlet mainfold. This was a problem that was (and still is !)rather common on older Porsches and mine did it frequently when hot. Comming down a long straight and letting off the accelerator,braking before the corner and "bang" - the K-jetronic flap is destroyed or bent due to back-ignition :( The cure is "the toilet flap", a lightly spring loaded flap that sits on the box that collects to the mainfolds. Any overpressure will open this flap to the outside world and not put big force on the system. Have seen other racers use a much simpler system : The kind of plastic conical plugs (end-seals) that are used for 30 to 50 mm plumbing tubes fits nicely into a slightly conical hole in the inlet mainfold. A small wire attached to the outer rim of the plug keeps it from dissapearing when blown away. Some area on the plug bottom is needed so use the biggest one possible. This can of course only be used on non-turbo cars !

BR, Carl.
Carl Blom

>>Motorola types MPX will fit. I dont have the MPI so dont know the exact numbers after "MPX".<<

Now that is very useful information (as ever!) Carl :oD How can we find out the correct part number?
Rob Bell

Rob, Dieter has one that he has opened up. Lotīs of pict. of the unit but unfortunatly no pict. on that specific part of the PCB where the pressure sensor is.
As the MPX series is rather new (around -95) there might be an older but similare one on the MEMS PCB...
Carl Blom

>> Motorola types MPX will fit

I've got 3 friends who wore in Motorola who are able to get parts etc very cheaply. Better getting the components than a full mems unit!
Bob Millar

I've just added few pictures of my old MEMS and specially a zoom on the MOTOROLA component.

Check it here : http://mgfcup.forumtuning.com/index.php?lg=eng&id=mycar_photos
Arnaud

Sensor Motorola 5141550T02 (this code seams to be manufacturing related only ) :(
says the sticker on my (Luc Vael's) broken ECU.
http://www.mgfcar.de/mems1.9/dk_DCP_5675.jpg

Anyway, here are to many ...
http://e-www.motorola.com/files/sensors/doc/data_lib/DL200.pdf
(670 pages !!)

Dieter K.

Interesting stuff starts at page 147.That damaged sensors housing has probably to be opend up in order to get the type of sensor and part number as the element itself is much smaller than the pictured box.... A custom made housing with an ordinary traceable sensor inside? With increasing age and dirt /oil and gases entering it can be a good thing to trace this one down. As said, they are cheap when bought at the right place compared to get a new MEMS ECU from the dealer ! Just wonder if the external one on the VVC is compatible ?

BR, Carl.
Carl Blom

This thread was discussed between 21/10/2003 and 24/10/2003

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now