IVA passed - nearly! Failed only on speedo

Failed yesterday at IVA test.
Over centre catches OK. California Vitaloni mirrors OK. Loud exhaust OK.

Failed on penultimate test, the speedo accuracy. Not possible to get stable and accurate reading.

I have VDO electronic speedo with Alfa 164 and 5 speed gearbox. I have inductive sensor and shielded cable earthed at sensor end.

I tried to get Alfa gearbox sender working with VDO but failed. Any ideas? Could it be broken?

I fixed VDO sensor on chassis to sense drive shaft bolts. Is it better to be perpendicular to the nut heads, or sensor in the same plane as shaft rotatation?
Bracket is 1mm aluminium plate. Could vibration be issue?

Can any inductive sensor be used. Ebay or RS?

Regards
Steve

Fault you are finding is the engine moving on it's mounts and the sensor is fixed on the chassis. Mount the sensor on the gearbox, use some thicker material for the mount.

I think there was some relevant advice in your original thread on the speedo sensor.
But hey, one issue ain't at all bad.
Re-test should be stress free if you can sort this out pronto.

Gear box mounted would be better rather than chassis mounted but given the Corse engine mounts are very rigid I doubt the engine moving is the issue.
A 1mm bracket is too thin for a sensor bracket so I suspect this is flexing with vibration & causing the issue, consistent gap is the key.
A 2 wire VDO sensor is absolutely fine, no need to swap the sensor. Drive shaft bolt heads are good for pick up & the sensor mounted vertically above the bolts is fine too.

Quote:

---

Originally Posted by Strat Fan

Gear box mounted would be better rather than chassis mounted but given the Corse engine mounts are very rigid I doubt the engine moving is the issue.

---

I had this problem with my Corse. I used a 3mm thick steel bracket but mounted it on the chassis. By the time I got to the SVA station the engine movement had caused contact with the sensor and ripped the end out. That was the only thing I failed on too and a new sensor and engine mounted bracket sorted it quickly and simply.
Well done.
Mick

Any ideas on whether to order new gearbox sensor and if this can be easily integrated with VDO speedo.
It would be the neatest solution

I originally used the standard sensor in the 164 box connected to a GTV electronic speedo. This was via a calibration control box to enable the speed to be calibrated. Worked fine and was 100% accurate.

Quote:

---

Originally Posted by Cadami

I originally used the standard sensor in the 164 box connected to a GTV electronic speedo. This was via a calibration control box to enable the speed to be calibrated. Worked fine and was 100% accurate.

---

The vdo speedo has a calibration function.
I just want to know how to check if the alfa sensor is working, should I buy a new one, and if they can be connnected.
Is the alfa inductive or hall effect. It changes the connections on the speedo.

Regards
Steve

Steve, I'd assume the box sensor works for starters as they're reliable but you could buy a new one. I'm unsure of the sensor type. You've obviously switched the sensor options on the speedo without any success? It maybe outside the speedo tolerances!
I'd reposition the VDO sensor to a box mount point to pick up the shaft input........ I've used that config for my SPA digital speedo and it works fine.

Just a quick one Steve, check all the nuts are in the same posistion as they pass the sensor, either all flats of the nuts or all points ..

mel


PS Well done young man.....looking forward to seeing it next year at the Kit Car Show or Silverstone...