It looks to me like this VDO 333-363 tach will work with the stock 1989 Ford 7.3 IDI sensor. Agree?
Does anyone know the Pulses-Per-Revolution of the Ford sensor?

VDO Series 1 Tachometers 333-363 - Free Shipping on Orders Over $99 at Summit Racing

 

Deleted post... wrong information on IP gear tooth count.

 

Copied from the VDO installation instructions:

2. Manual Calibration with a known value

If you know the exact calibration value for the vehicle and
type of sensor you are using (pulse-per-revolution), you may
use that value to manually calibrate the tachometer.
To calibrate your VDO Tachometer manually:
1. Press and hold in the button on the tachometer as you
start the engine. Hold in the button until the word “PULSE"”
is displayed on the LCD readout.
2. As soon as you see the word “PULSE" release the button.
After a few seconds, the display will start flashing a series of
numbers (factory default setting) that you can change to
represent the impulse-per-revolution value of the ignition
in your vehicle. For example, a number like “P 14.70” will
show on the display, with each digit flashing in turn from
right to left, except the right-most digit, a zero, which is
fixed.
3. As each number flashes, press the button and hold it
until the correct digit appears. Refer to Diagram H.
For example, let’s say the number that represents the cor-
rect calibration value for the diesel engine and ignition sys-
tem in your vehicle is 16.5 pulses-per-revolution. When
you begin the manual calibration process, the LCD displays
a default value. When the first digit starts flashing, press
the button to start cycling through the numbers. When the
number “5” appears, release the button.
At this point, the number “5” is set, and the digit to its im-
mediate left begins to flash. Press the button again, and
hold it until the number “6” appears. Release the button.
Repeat the procedure until the “1” appears. Again, release
the button. At this point, the correct calibration for the
tachometer/ignition combination has been properly set...in
our example, 16.5 pulses-per-revolution. After a few sec-
onds, the value you have entered will be downloaded into
the tachometer’s microprocessor, and the LCD display will
automatically revert to its normal mode.

It appears that you can manually select any Pulses-Per-Revolution figure all the way to a tenth of a PPR. Does the 52 tooth IP drive gear run at 1/2 crankshaft speed so that there are only 26 PPR per crankshaft revolution?

I have a 1989 F350 with the factory tach. I am transplanting the 7.3 and ZF-5 into a 1958 F600 and the factory '89 tach doesn't come close to matching the '58 gauges while the VDO is a very close match. That's why I'm looking for an alternative for the tach.

PS: I just saw the phone number on the installation page and called tech support. He told me that you can manually select any PPR from .5 to 399.5 and he assured me that it will work with the Ford sensor so it looks like I'll be buying this tach.

 

Yes, the IP is 1/2 the crank speed. Same # teeth on the cam gear and IP gear.

 

When I built my custom tach, I divided by 53 to get RPM. The cam gear has 106 teeth, and runs at 1/2 crank speed.

 

post up if it works

 

Will do.

Upon further review it appears that the crankshaft gear has 53 teeth and the cam and injector pump gears have 106 teeth so the PPR for setting the tach is 53.

 

any progress?

 

bought one yesterday.
followed the programming sequence
4-8C
53 pulses
it resets fine, but will not read RPM.

does anyone know if the stock sensor is hot on one wire?
trying to use stock equipment.
starting to thinking maybe another sensor is required

EDIT:
i just swapped the sensor with a bran new motorcraft tach sensor.
AND THE TACH LIVES!!!
i used the stock pigtale from a spare harness.

brown and yellow wire on pin #8
green and yellow on pin #7
constant 12V pin #5
switched 12V to pin #4
ground to pin #3

select value set at 4-8C
pulse value set at 53.00

THIS TACH IS A VIABLE OPTION FOR OUR IDI'S WITH THE STOCK TACH SENSOR

 

The 7.3 and ZF5 are mounted in the '58 F600 but I still have to get the Brownie and Dana 80 rear axle installed and then I'll worry about gauges.

 

Update:
The 1958 F600 with the 7.3, ZF5, Brownie and Dana 80 are up and running. I've driven it up and down the county road a couple of times now. I wound up buying a custom aluminum radiator and mounted 2 low profile electric fans on it. At idle and low speeds on the road the temp goes up to 190* (where the thermostat starts opening) and stops. I have the fans set to come on at 210* and 220* and they never turn on.

Today I installed the VDO 333-363 tach. After getting it wired up using the factory tach sensor I followed the instructions to set the pulse at 53. The tach is working fine. I don't know if the sensor/tach is polarity sensitive or if I just got lucky but everything works. If the sensor/tach is polarity sensitive it would only require switching 2 wires on the back side to reverse the polarity.
And the tach looks "period correct" in the '58.

 

The tach sender outputs an AC signal which is by definition non-polarized.
However, if you were using an aftermarket tach along with the stock tach or wiring, you would need to watch for polarity - the stock setup grounds one wide of the tach sender and is looking at the other wire referenced to ground.

So, obviously if your polarity is incorrect on your sensor, you'll end up 'reading' ground(and probably ground out the sensor entirely as well)

 

Just adding myself to this thread for future use