RPM reading in Diesel engine (1 Viewer)
- Thread starter urib
- Start date
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Tachometer does not go to alternator. Must be either a mechanical tach or a sensor attached to the harmonic balancer to measure RPM.
Check with @Dave 2000
In some vehicles you can get a signal from the alternator to operate a tachometer. I looked into it a while back for toyota diesel swaps but gave up because I had other options.
@urib it would be helpful if you give more info regarding what engine and trans you are using as well as which vehicle.
@urib it would be helpful if you give more info regarding what engine and trans you are using as well as which vehicle.
Dave 2000
Not all Land Rovers are useless!
AFAIK most 80 diesels take a signal from the fuel pump, there are two electrical cconnections on the pump, one single wire to stop solenoid, and a twin cable to a speed sensor.
Note, base models did not get a tach, unsure if the pumps were identical?
Regards
Dave
A tach signal can be obtained from the alternator if using Dakota digital. All you have to do is solder a wire to a strand of the copper coil on the alternator and run that to the Dakota digital device. Then from the Dakota digital device to your tach.
Does it have to be calibrated due to variances in pulley sizes. etc?
Correct. So calibrate based off a known gearing ratio or calculate based on pulley size, crank and alt.
you would think so.
If you count the pulses per rev of the alternator and know the ratio of the main to the alternator pulley, then its a simple ratio.
You'll need to get the signal before its converted to DC, of course.
If you count the pulses per rev of the alternator and know the ratio of the main to the alternator pulley, then its a simple ratio.
You'll need to get the signal before its converted to DC, of course.
