Morris Minor Owners Club

Hi I've bought a rev counter so i can improve my fuel consumption. the wiring instructions are not that good. i have to connect it to an rpm signal. where would i find one of those. my first thought was coil.

Yes, you could, but it does largely depend on the type you have. Can you post more details?

Wiring diagram[frame][/frame][frame][/frame]

Exactly HOW will this improve MPG ?? Please explain - I'm after every MPG improvement I can find......

Not sure how a rev counter will help with fuel consumption.
Better to read the road ahead, don't accelerate towards red lights and traffic jams, also don't try and close the 1 cars length gap in front of you at 100 mph, you don't get to your destination any faster.
Tyre pressures play a part too, don't use cross ply pressures on your radial tyres, try something around the 30 psi mark.

It may well not improve it by much. but it will help me change gears at the right time. but how do i connect it up.

How do you know what the correct time to change gear is? It varies according to driving conditions, far better to listen to the engine.
Don't think much of the wiring diagram
Car must be neg earth
Try S to coil black/white, + to coil white, - to earth. If that does not work swap wires to the coil over

Don't think much of the rev counter idea! How will counting revs help anything? If you don't know when to change gear....well

All i want is some advice as to where i would get an rpm signal. + or - on the coil

No idea - but if you get it wrong it may blow the electronics...... I suggest on the + side (assuming neg earth car) you would only see the 14 volts of the car system. But don't take that as advice from me that the - side is the one to use.
You'll be fitting a vacuum gauge next.....and maybe a new coil ......

bmcecosse wrote:.....and maybe a new coil ......

hahaha

Looks like my instructions are the best you will get. What make of rev counter?

All i want is some advice as to where i would get an rpm signal. + or - on the coil

Should be the side of the coil that goes to the distributor, which should be the - side if the car is negative ground.

Same side as the points I would think, the other side will just see 12 volts.

Exactly HOW will this improve MPG ?? Please explain - I'm after every MPG improvement I can find......

BMC you could try the old trick of attaching magnets to the fuel tank, decreasing the inner diameter of the fuel line so less petrol is used, screw the jet adjusting nut right up or fit one of these which tells you everything:


[frame][/frame]


Let me know how it all goes

Hahahahahahahahahaha......tried all that already. Looks suspiciously like the dreaded vacuum gauge you have there.........

Ditch the single SU and fit twin Webers and one gauge to each carb. That way I reckon you could easily benefit from an extra 5mpg.

Here's an honest one:[frame][/frame]

he he he brill

Robbiet9999,

I think in summary the car must be wired with 'negative earth' - if it is still positive earth, the rev counter you have will not, and cannot be made to work.

Assuming that it is now, or was before, negative earth, the +12v ignition connection can either be made directly to the fuse for the indicators and wipers, or to the ignition side of the coil (SW or +) with an inline fuse (1A) fitted. The 'rpm signal' comes from the distributor side connection on the coil (CB or -). The coil connections need to be checked as they may not be correct now - coils will work even if connected the wrong way round, but should be made correct as part of the rev counter wiring.

The '-' on the rev counter should be connected to the body and the 'lamp' to the speedo instrument lighting.

On a standard engine, tickover should be around 700/800 rpm and max revs no more than 5,500 rpm. Cruise at max of 4,000 rpm. All this assumes that the engine is in good condition and the hot oil pressure is at least 50 lb/sq in at 50 mph in 4th gear.