Getting a OEM petrol engine tacho to work with a diesel engi

[up2nogood]

Anyone know how to make this happen?

Is there an adaptor for these somewhere?

From what I know, the petrol tach works off the coil. The diesel tach works off a sensor on the crank/flywheel/front pulley. But I don't have a crank sensor......

Oh, it's for a 95 Land Rover Disco.

[bazzle]

Take a tapping from alt exiting cct.
You will need to cal it somehow.

Bazzle

[F'n_Rover]

A VR sensor off a EL ford and a modified input circuit on the tach should work.

[udm]

A VR sensor off a EL ford and a modified input circuit on the tach should work.

Excuse my ignorance.. whats a vr sensor and what would you modify to the input circuit on the tacho?

Ive stuck a 1hz into my fj80 a bit more than a year ago, and have never got around the tacho thingy.

Ulises

[F'n_Rover]

A VR sensor off a EL ford and a modified input circuit on the tach should work.

Excuse my ignorance.. whats a vr sensor and what would you modify to the input circuit on the tacho?

Ive stuck a 1hz into my fj80 a bit more than a year ago, and have never got around the tacho thingy.

Ulises

vr sensor = variable reluctance. ( its a magnet with a coil of wire around it, most cars would use this kind of thing as they are cheap and very reliable) They put out a few volts ac when a steel cog moves under them.

Get a cog that matches the tach not the motor (as in number of teeth)

A tach input would be set up for a much higher voltage - You can either make up a black box to step up the vr sensors output or change the tach internally.

I've never done this and never will, but it's doable - although there's probably a better way.

[F'n_Rover]

Also another possable option - early omc outboard tachs were driven off the alternater stator, I don't remember the number of poles but you could get lucky.

[up2nogood]

Might see if VDO make a sender unit. I'll have to take from the alternator.

But with aftermarket tachos, they are adjusted in the tacho.......

[Nev62]

I'll check my setup and let you know, I'm running a diesel and using the OEM tac in the dash on the FJ62 (was originally petrol)

[Modified Toy]

in most tacho's there is a screw that you can turn to adjust the input into the tacho it self regardless of what type of sensor you are using as the pick up on the engine.

[up2nogood]

Thanks Nev. Look forward to seeing what you can find on your car.


I know the after market units are adjustable, but can you adjust the stock units?