I have had no luck finding how the original dash tachometer can be connected to the larger engine.

Vehicle is (Toyota Surf LN130, 2nd Gen, 3L, 2.8 litre) pre-facelift 1991. Previously it had a turbo 2.4 diesel with auto trans, and it now has a 2.8 naturally aspirated diesel with manual transmission.

The dash has idiot lights for  "Turbo" and "Engine Check" so indicating it was the original with the 2.4. The Turbo light never comes on and the Engine Check light is on permanently (because, no doubt some things are not even present or connected to the ECU).

I have been told variously that the feed for the tacho comes from the vacuum pump, the alternator or the injector pump. I have also been told the signal could be in one of several waveforms, but I have not found someone who can actually hook it up.

It may be that swapping the dash or the alternator could allow a connection. I won't be swapping the injector pump as that has just been reconditioned at 310,000 kms. I guess another vacuum pump is a possibility too. The vacuum pump does occasionally get the small tube blocked with oil sludge and stops supplying vacuum for the 4WD axle engagement on the front axle. This has happened twice in 100,000 kms. Once paid a 4WD centre $700 to fix it and they did everything but fix it. Actually they just removed vacuum tank, replaced actuator and failed to find a wire short. So that's why I prefer my own maintenance.

So I would be much obliged is anyone has some knowledge on connecting Totota tachos to Toyota engines.

Also possibly known as Hilux, Surf, 4Runner and perhaps more monikers. Cheers.