Can I modify my fuel pump for a tach output. (1 Viewer)

[Gengis]

Hi all

I need a tach output from my Hz fuel pump, as fitted to the HzJ76. Can this be modified /added by myself or woud it have to go in the the pump shop.

Would the pump already have the "reluctor " fitted and just need a pick up fitted in the right place?

I need this to drive a after market engine monitor, and the alt output gets messy and needs to be calibrated whereas a know number of pulses per rev needs no calibration.

G

 

[John Young]

I'm faced with the same desire; adding a tach. I'd been thinking of using a hall effect sensor. This has the advantage of being totally accurate. You just need to put a tiny magnet on something that is rotating.

Amazon product ASIN B078N5S9KT

 

[Gengis]

Thats a last resort John, but if something like this can screw into my existing pump, I would like to know, because that would make it very easy.
G.

 

[John Young]

Per this page, "This sender unit screws into the gearbox bell housing to detect the engine revolutions from the flywheel"

I'm pretty sure this is a hall effect sensor. Are you looking to monitor engine RPM? If so, perhaps you could drill and tap another hole in the bell housing to use the same magnet as for the stock one. It's just whizzing around there doing nobody any good 99 percent of the time when it is not activating the stock sensor.

Maybe I'm not understanding. Am I missing the point? Maybe you could tell us all a little about your engine management plans. Sounds interesting! I've wanted to do sort of similar things to my 1HD pickup truck Golden Boy, given it came without a tach on the dash.

 

[roscoFJ73]

"This sender unit screws into the gearbox bell housing to detect the engine revolutions from the flywheel"

The part is definately a 1HZ 1HD T tach sensor that screws into the injection pump, its just the dialog they have added is incorrect. Its also fits the 1KZ T and 1PZ and some of the later 3B 11B and 14B engines with rotary injection pumps in Dynas and Coasters.

 

[roscoFJ73]

I looked through the parts list for the 1HZ pump on a south african spec 08 model and couldnt see any part remotely like the "reluctor"

 

[John Young]

I suspect I am not moving the ball forward at all, but...

Here's an exploded diagram from page 170 of the 1HZ FSM:

...which unfortunately does not show what the sensor is sensing. And here is the pump with the guts exploded:

Here's another couple of not-very helpful mentions of the sensor.

And here's the circuit diagram from the RM183e manual: