Thread: New member with a new Disco

Can't be sure my tacho is 100% spot on, buts its close. My pulley measures 65mm OD

There are also different sized pulleys for the PS pump where the alt belt drives from. The alternator side of the pulley from my DD '86 Rangie and '88 Rangie parts car were a slightly different size. One had both the same size, the other had the alternator size slightly smaller from memory. Havn't taken a great deal of notice with the one on the Disco tho.

Your stalling when cold issue could be another issue all together. Stepper should raise the idle when cold. Maybe its not working and someone has raised the base idle speed to compensate.

I took the stepper out and gave it a clean, i held it out and started the car and it motored in and out fine. When it is hot, it adjusts itself slightly. I'll measure the pulley this morning and see what comes of it. Hopefully I can work out a ratio discrepancy and just do some math to work out what the rpm actually is.

Rick - we have a winner! My pulley is 55mm OD. Which means I displaying 120% of my real RPM. So every number I see needs to be knocked back to 85% of what I see. So, at 105 I am actually revving at 2500, not 3000 as displayed. Problem solved!

Seems the alternator was replaced at some stage and the pulley wasnt swapped.
With the 245/75's you will be out slightly by 1-2 kph.

The tyres should help bring the speedo into line then. By GPS it is out 3-5km from 90-110 with it gradually getting worse. Should help line things up now.

Part number on top of the alternator makes it a 120A Marelli unit - 63321358.

I'm looking at coil spacers, in place of a full suspension lift, mostly due to cost. Spacers are sub $100 where kits are $500 and then we'll up from there.

Are coil spacers suitable? Will stock shocks cope with a 30-50mm lift?

Shocks should handle 50mm but I think you will get spring bind with spacers