Tachometers? (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

PERUVIAN

PERUVIAN

Joined
Jan 28, 2010
Threads
49
Messages
196
Location
PERU
What do the BJ/HJ cruisers have for tachometers?
In the FJ obviously it is in the center of the console.. but with my 3B switch.. I know that the way it us currently set up will never work again..

What do you guys do to maintain an original looking panel and get a functional tachometer ?

I do not have anything here in country to compare it to.. at least where I am-

Thanks
Todd
 
The tach is the factory style mounted in the center of the dash (about 2.5" diam). It goes in the exact same location of the FJ just a different scale (yellow line at 3500, red line at 4000). The sensor for it is a flywheel sensor and the other half is on the bell housing, so I believe it is a magnetic sensor. If you have the sensor in the housing any tach with that RPM range that takes a magnetic sensor sending unit should work.
There are a couple local guys I can talk to that might be able to send you a diesel tach from Canada that is a factory unit.
If you are interested then PM me.
 
I think Sheldon at G&S has a bunch of 60 series diesel tachs. If you're wanting to use your gasser tach with the diesel pickup, then you need to buy a converter like I did for my conversion. I used the one from Dakota Digital...bought off of Ebay. Works very well...but is sensitive to electrical surges. Doesn't do much, but the needle blips a little bit when I first turn on the blinkers or use the power window.
 
So.. the factory diesel tack takeoff is a magnet sensor on the bell housing..
The convertor takes into account the number of teeth on the flywheel ( pulses ) and then converts it into a single pulse as if from a spark plug lead? Which convertor do you have.. the (w) on the laternator model or the pulse reading unit?
I think G&S /or/ junkyard picking sounds like a good idea--

Todd
 
I just bought the regular Dakota Digital converter for mine...to take the hall effect signal from my diesel bell housing sensor and replicate the igniter signal that my gasser tach wants to see. The complication I had was that my FJ80 cluster is a one pice unit with the tach and speedo in one. With your separate tach, I think retrofitting a diesel tach is the way to go also.
 
I think the guys name is Astr on here.

He did a write up about how he made the stock 60/62 tach work with a diesel engine (any engine for that matter)

you get an ABS wheel sensor....pretty much all 2 wire abs sensors are the same

for my engine (4bd1t) i'm mounting it on the flywheel housing.

I'm drilling a small hole and mounting it about a 1/4 of an inch from the flat of the flwheel (just behind the teeth there is a nice flat area)

I'm drilling 3 holes at equal distance from each other...notching works too. all your trying to do is cause a break in the magnetic pull of the sensor

without any recalibration your oem tach will pick up on the signal with no issues/no recalibration.

search Astr on here as i cant remember if which wire goes to a pos. lead and which wire goes to your tach.

i got my abs sensor for less than ten bucks from ebay...i'm too lazy to get one for ten bucks at the local junk yard.

this can be made to work on the engine crank pulley or harmonic ballancer even an accessory pully so long as it' rotates the same 1:1 ratio as the engine. If you can fit the little abs wheel sensor and make 2 notches/drilled indentions...it will work

my engine/his engine was a 4 cyl

check in his thread to see if you have to add any notches/indentions for different cyl engines...as i don't recall. I don't think it matters but might be worth reading.
 
That makes complete sense..
I have a sensor like that on my JD4045 -
But we use it to detect for a set RPM to disengage the starter with the autostart function setup-
 
If you're looking for an easy to mount hall effect sensor the guys at sdsefi.com make a nice unit that goes with their engine management systems.
 
I have an Isspro tach which uses the OEM pickup from a 3B bellhousing on my FJ55. Works great.
 
Landcruiser Diesel tachos use magnetic reluctance pickups from teeth on the fly wheel (B=110, H=108) , the 10 volt peak-to-peak sine wave is converted to pulses with a voltage comparitor (vs ~3V) then the pulses are divided by 32. Next a frequency to voltage conversion chip provides an output for the needle driver (weak electric motor pushing against a spring).

[the last 2 parts (freq conversion / needle driver) are almost the same as for the 6 cylinder petrol tacho, because 108/32=3.375 pulses per rev (slightly different amplification required) ]

bye.
 
Last edited:
A recent post showed that the petrol tacho uses fairly large capacitors at its input (to reduce interference and voltage spikes). These can block weaker signals so quite often a Toyota tacho won't work in other vehicles. The post said that replacing the caps with smaller value ones got it working with a simple magnetic reluctance/square wave shaper input.

A reply said it was even possible to by-pass the caps altogether with no ill effects (overly conservative Toyota again).

This got me to thinking - a comparitor chip and a counter/divider chip between the bell housing pick-up and a Toyota petrol tacho should cost less than $20. A micro-controller chip solution (with accurate 108/110 to 3 pulses per rev translation) should be around $10 to build in small quantities. With mark-up (profit) and postage it should be deliverable for $30.

Are there any entrepreneurs out there who see enough market in the diesel transplant boom to provide a (sealed) translator circuit to go between the sensor and the original petrol tacho?
Magnetic reluctance pickups and suitable diy mounts for the bell housing may also be included to make complete kits.

Interest ?

bye.
 
bgennette said:
This got me to thinking - a comparitor chip and a counter/divider chip between the bell housing pick-up and a Toyota petrol tacho should cost less than $20. A micro-controller chip solution (with accurate 108/110 to 3 pulses per rev translation) should be around $10 to build in small quantities. With mark-up (profit) and postage it should be deliverable for $30.

Are there any entrepreneurs out there who see enough market in the diesel transplant boom to provide a (sealed) translator circuit to go between the sensor and the original petrol tacho?
Magnetic reluctance pickups and suitable diy mounts for the bell housing may also be included to make complete kits.

Interest ?

bye.
Click to expand...

If there is interest I'll build them...

But $30 shipped is not gonna happen. I just paid $20/board for some small (5 sq in) custom PCBs - thats for the PCB alone, not including components - and it was the best price I could find outside of China. Add $10 for components, plus probably $10 for connectors and an enclosure. Plus my labor to solder them together and program the processor.

... not $30.
 
+1 for tiny tach...install was so easy, too.
 
I have a project here I am about to begin. Seeing if I can use an aftermarket tacho to drive the stepper gauge in a stock Nissan cluster.
 
You must log in or register to reply here.

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)

Share this page

Back
Top Bottom