Thread: Tune Resistor Query

Folks,

I'm new to the forum. Purchased a nice 1995 MY RR Classic LSE when I arrived in Perth last year as a rolling restoration project. I put in a reconditioned 3.9 motor (new camshaft, new seals) and took the opportunity to replace the engine wiring loom at the same time. The engine now runs well at speed, but idles erratically - have looked at all the normal culprits (new MAF, new stepper motor, replaced the fuel pump and pressure regulator on rebuild, new leads and plugs, no vacuum leaks, etc.). I'm starting to think its the ECM. The unit runs much better if I disconnect the tune resistor, but I suspect that may be because the ECM degfaults to limp home mode.

My question is whether this Australian model RR should have a tune resistor or not. The old wiring loom I took off the car had no tune resistor, but the new wiring loom purchased from LR Classic Parts had a red tune resistor installed. The shop manual for the 1995 model references a red tune resistor, but I've also seen in other forums that after circa 1993, a tune resistor was not installed and the appropriate map was incorprated into the ECM programming.

Can anyone with a 1995 MY RR Classic (or 1995 LR Disco with the 3.9 engine) tell me whether they have a red tune resistor installed? The tune resistor should be taped into the wiring loom about 30 - 45 cm away from the ECM mounted on the RHS of the drivers footwell. It is connected to the wiring loom via a blue, 2 pronged plug.

For anyone in the Perth area, I have a Lucas 14CUX ECM reader (ECUMate from Steve Heath Engineering) that can tell whether of not a tune resistor is installed simply by pluging into the Testbook diagnostics connector, so if you would be willing to let me plug it in and check, I'd be willing to pay you a beer, or at least give you a chance to run some free diagnostics on your own injection system.

Great forum by the way. Sorry for the long 1st post.

Thanks,

CanadaRover

Originally Posted by CanadaRover

For anyone in the Perth area with a 1995 MY RR Classic

that can tell whether of not a tune resistor is installed simply by pluging into the Testbook

so if you would be willing to let me plug it in and check

Send me a PM