MFA kind of working!

[muppet]

hi guys ive read the other threads on mfas not working but none really that helpful 

the problem i have is that the mfa only kind of works as in the temp can be seen and thats it!!!

the rest of the readings are just left blank with the normal hyphan (-----) signs? ive tried taking out the clocks fuse for a half hour or so and still no diffrence! any help please ?

[rubjonny]

either the clocks are bust or perhaps the speed sensor on the back of the speedo has gone, or the wiring plug to it has come loose

[muppet]

either the clocks are bust or perhaps the speed sensor on the back of the speedo has gone, or the wiring plug to it has come loose

thanks rubjonny 

excuse my ignorance lol but what part of the speedo would be the sensor on the back? and where is the wiring plug?  thanks

[maxp]

I've noticed that if my oil temp sensor is reading <50 deg c it also reads '------', after that it reads it in multiples of 2

[muppet]

the only problem is that nothing comes on lol its just blank could this be because of vacuum hoses not being connected properly because i know i have a vacuum hose problem!! i hear a whistle when i slowly rev it up to about 1200 revs (1991 16v)

[rubjonny]

even with the vac hose off on my driver the mpg gauge still worked, it was wrong but it still worked
if you take the clocks out you'll see the speedo sensor, its screwed to the back of the speedo next to the cable.  It has like 2 clips on the side which hold it shut on the electrical connection to the clocks.  Sounds more complicated than it is, if you have a set o clocks in front of you you'll see what i mean!

It may have had a non-GTI speedo fitted and the speedo sensor wasnt bolted back on, the non-gti speedo has a blanking plate fitted where the sensor needs to go, you lever the plate out and screw the sensor on

[muppet]

i dont get it though it worked a while ago when i drove from east london to swansea llol
i was very concious about petrol consumption but £50 got me there n back with some to spare!!!!

after that when i took the dash back out to change the bulbs for the speedo it stopped working!!! i did take the power off the battery cos i was told to do so by a mate and im guessing it was after that it stopped working!!!!

that was the first time i ever took out a dash and that by myself so something might not have gone back on properly.....

i did post about the MFA rubber cable that i couldnt seem to get off unless i tugged it really hard could i have pulled it out the other end or damaged that in the process??

[rubjonny]

the other end runs to the chunky brake pipe off the back o the inlet manifold.  You might have damaged the vac unit but that wouldnt explain why the other bits stopped working too, unless you trashed the PCB.  my money is still on the speedo sensor, since as I said even with the vac line off on my Driver tall the other settings still worked, and the mpg display showed something though it was wrong

[muppet]

thanks rubjonny ill take it all apart again and see if i have forgotten to tighten up something as well lol need to take it apart anyway to change the colours of the speedo needles!!!

ill keep it posted

thanks

[muppet]

oh ye another thing rubjonny would it make life any easier if i took the hole dash out or just enough of the dash to get the speedo out? lol last time it was a nightmare trying to get it in and out to test it all with the surrounding dash still in!!! :embarassed: