Economy gauge playing silly buggers 1985 e30 m323i

[Jacko 2156]

Not a major just wondering if its an easy fix

My economy gauge sort of glitches occasionally while stopped, like itll go all the way up to 50mpg then back to zero and then back again with the engine at idle. Taking off and it sorts itself out again.

Cheers, Chris.

[*Glenn* 854]

Not a major just wondering if its an easy fix

My economy gauge sort of glitches occasionally while stopped, like itll go all the way up to 50mpg then back to zero and then back again with the engine at idle. Taking off and it sorts itself out again.

Cheers, Chris.

The guage gets its signal from the AFM (load signal) it could be a problem there or it might be the circuit board in the dash. Does the car run properly ?? and does your SI (service indicator) work properly in the dash, does the fuel guage or temperature guage flicker or move around too ??

[Jacko 2156]

The guage gets its signal from the AFM (load signal) it could be a problem there or it might be the circuit board in the dash. Does the car run properly ?? and does your SI (service indicator) work properly in the dash, does the fuel guage or temperature guage flicker or move around too ??

Everything runs fine. The cold idle is a bit high but other than shes beaut. It must get a speed signal as well a vacuum signal, maybe thats whats playing up?

[*Glenn* 854]

Everything runs fine. The cold idle is a bit high but other than shes beaut. It must get a speed signal as well a vacuum signal, maybe thats whats playing up?

The guage gets its vacuum signal from the AFM (load) there is no vacuum connection, its only an electrical signal from the AFM.