MFA Q's

[red-rado 0]

My MFA is giving completely duff readings.

 

MPH is often 10-20mph too slow

Miles travelled is normally 2-3 miles further than actually travelled

MPG is around 12-20mpg too low

Oil temperature seems accurate

Time is accurate.

 

What would cause these symptoms? Just a host of duff sensors or the MFA unit itself?

 

Its a 1990 KR 16V

Cheers.

[Supercharged 2]

What size wheels and tyres do you have?

[red-rado 0]

16x8 with 205/50/16

[Supercharged 2]

I think you've answered your own question there... :)

[red-rado 0]

Yes, that really explains why the digital mileometer OVER reads...

 

Also, the outside temperature guage reads -40*c

[dr_mat 0]

I think your MFA was calibrated by a passing badger at the VW factory.

Or it's faulty.

Check that it's getting reliable 12v.

Don't know where the data comes from for the 16v, but I would imagine there's a gearbox sensor for distance travelled and it uses manifold pressure for the mpg. My MFA doesn't report "MPH", btw. Or do you mean the average MPH? That's always lower than you expect ..

[andreiz2132 0]

the outside temperature guage reads -40*c

 

maybe this happens because your outside temperature sensor is not connected at all. try looking for the sensor and if it is connected. you can find it on your front bumper, on the right side (it's on that black plastic grille, under the turn right signal)

[Yandards 0]

Yes, that really explains why the digital mileometer OVER reads...

 

Also, the outside temperature guage reads -40*c

 

The tyre size is the reason your MPG etc readings are off.

 

The -40C means the sensor is busted or missing so you will need a new one.

 

Dr Mat, the early 16v uses a cable driven speedo but the MFA still works with the same data input as the later units, the speed signal from the speedo is fed into the MFA, the only place the gearbox pickup goes is to speedo, it does not directly input into the MFA (Just for your info of course ;))

[sparks 0]

mfa outside temp -40

i dont have that on my G60 i have oil temp but not outside temp was it an option on later cars or vr6 only mine an J reg ive only just found mfa 1 aswell ive been runing around thinking there was only one setting mfa 2

found some numb nuts had put the brown plug in the wrong way around under the dash shessh!!!

[Yandards 0]

mfa outside temp -40

i dont have that on my G60 i have oil temp but not outside temp was it an option on later cars or vr6 only mine an J reg ive only just found mfa 1 aswell ive been runing around thinking there was only one setting mfa 2

found some numb nuts had put the brown plug in the wrong way around under the dash shessh!!!

 

No, outside air temp sensor should be fitted to all models but the MFA will skip it if one is not fitted, you should find it in the r/h brake cooling duct area.

 

Unless you have a factory fit electronically controlled a/c panel then it will skip the MFA outside air temp.

[sparks 0]

ok next question i cant find one it doesnt have electroinc a/c so how much is a new one i know the guy before me fitted a new engine so looks like he "missed " alot of the other stuff that went back

cheersss

stu .