Rev counter a bit dicky

[SWB ANDY]

evening folks
could some point me in the right direction, the rev counter in the shorty tends only to work when it feels like it , when it does work it will stop working again if it gets to approx 3000rpm, not to sure where to start looking to even fix it, still on the steep diesel learning curve .
thanks in advance for any help

[RedSector]

evening folks
could some point me in the right direction, the rev counter in the shorty tends only to work when it feels like it , when it does work it will stop working again if it gets to approx 3000rpm, not to sure where to start looking to even fix it, still on the steep diesel learning curve .
thanks in advance for any help

get the FSM might be a good point to start

It is most likely the sensor for the RPM giving dodgy information to your tacho.... next would be a short in the wiring and lastly the actual tacho.

[SWB ANDY]

redsector
where would i find the sensor for the rev counter, any pics would help, if it was a petrol i would not have a problem, but as i said still learning.
thanks

[RedSector]

redsector
where would i find the sensor for the rev counter, any pics would help, if it was a petrol i would not have a problem, but as i said still learning.
thanks

Dont feel bad, most people dont know where it is either.

I am not 100% sure but fairly certain (75%'ish) - That you will find it on the fuel pump as part no MB658726.

Someone will correct me if I am wrong.

Hope this is of help

[peter54smith]

sender taco unit

hi guys just a quick reply to your taco problem i had a similar taco fault on my 1996 pajero 2.8 the sender unit is mounted on top of the fuel pump on the 2.8 and mounted on the rear of the alternator on the 2.5 my prob was a cracked circuit board on the back of the taco dash mounting hope this is of help best regards from wales uk

[SWB ANDY]

how do peter54smith
good to see some one from gods own country (wales), i am originally from north wales, been in oz for nearly 5 years now and loving it, is the uk still a basket case or are things getting better.
oh and thanks for the help

[Roadrunner2013]

The tacho sensor on the 2.8TD is at the side of the mechanical type injector pump between the pump and the engine. It's pretty inaccessible and requires the injector pump to be removed, PITA job, but first check the wiring and plug on the pump first. There is a test sequence in the manual. The other place is the PCB connection of the tach which suffers from dry joints. The connections can be replaced with 3 wires soldered to the PCB.

[Swbpaj94]

Had the same problem on my SWB NJ Petrol

Does anyone know where to locate the tacho sender on the 6G72? I've done some looking around and found a wire unplugged but don't think its the tachometer. The wire I found is on the chassis right next to the right front wheel arch.

[stumagoo]

6g72 reads it's revs from the dizzy. A signal goes back to the ecu and the dash cluster. If your engine runs but the revcounter does not work then it's more likely in the cluster as the ecu uses the rev signal in its workings to set fueling and timing. Without it you would get a ecu code and the engine probably won't run. Certainly it would not run well. I would suggest looking for a dry solder join on the cluster.

[seivad]

Rotation Sensor

As mentioned above in the post, the sensor is on the side of the injector pump. The water in the fuel sensor is often picked out as the source of the tacho signal - keeps cropping up.

[Swbpaj94]

6g72 reads it's revs from the dizzy. A signal goes back to the ecu and the dash cluster. If your engine runs but the revcounter does not work then it's more likely in the cluster as the ecu uses the rev signal in its workings to set fueling and timing. Without it you would get a ecu code and the engine probably won't run. Certainly it would not run well. I would suggest looking for a dry solder join on the cluster.

The tachometer is stuck on 3000rpm when the ignition is on without the engine running.

[stumagoo]

The tachometer is stuck on 3000rpm when the ignition is on without the engine running.

Definately sounds like a dodgy gauge not an issue engine wise. easiest fix is another cluster (as long as it is working)

[fangios]

I too have a problem tacho, on an NL 3.5 v6.

Mine is just randomly dead, then i look at it again and its working. I have tried banging the cluster when it is dead, but it doesnt help (thinking along the lines as suggested previously of a dry joint in the cluster).

Any thoughts, should I pull the cluster out and go over it as a first step?

[stumagoo]

taht would be my thought, I found on mine (my wagon has a NJ cluster but NL loom engine etc) the rev counter does not work - was not sure if it was cluster or wiring/engine- I was able to confirm cluster when removing as I could get a rev readout by connecting an after market rev counter (or a multi meter that reads revs) to the correct pins

[tin]

I've got the same issue on my 2.8. I'm pretty sure it the PCB or the servo motor (at least in my case), because if I tap the gauge clusters the tach comes back to life.