My MFA

[bigben 0]

the time is fine and the temp but the MPG is always at 99.9 anyone any idea why it dont work?? (when i got the car it didnt read right but for about 2 days it seemed to work but i was still gettin 78MPH under hard aceloration)

 

and the average speed bit always seems to be low like when i go on a 30 mile journy at nothing beloe 80 it reads bout 40??

 

cheers

[Henny 0]

Hiya, bigben, if you do a search for "99.9" you'll find a load of posts here about this problem. It's normally a vacuum hose having either split, come off, or become porus in the engine bay or on the back of the clocks themselves...

 

The average speed thing sounds about right to me... Next time you go out on a run, reset the MFA when you're doing 70ish and see if it stays about 70mph on the average speed... If it drops a lot while you're still at 70, then there's a problem.

 

If you are starting it at the start of the 30 mile trip, unless you can hit 80 in 0 seconds, and stay there until you stop (with no time to slow down!) your average speed will always be MUCH lower that you'd think... I'd bet that your 30 mile trip took about 45mins to complete, from engine start to engine off, so 40mph average is spot on! 8)

Remember, acceleration and deceleration times, time at junctions and lights, time before setting off while the engine is running, time checking the MFA at the end of the journey are all added into the average speed....