Octane setting

[harborman]

In trouble shooting my starting problem now solved, I discovered a wire disconnected on the LH or EZH computer. The wire is green and has a matching connector. It was unplugged and is located right by the computer connectors. It appears its for lowering the octane requirement. I think it said it retards the spark 3 degrees.

Do you run it connected or not? Mine came with it disconnected and I have not tried to connect it yet without finding out more. I have been using 93 Oct gas.

[riber.bentsen]

Disconnected = high octane

Connected = Low grade fuel.

Stated by Landseer (asked same question)

Edit: Just looked at a chart showing fuel rating for different 928s, and according to that, your car should be running 95 octane, so maybe you should try and connect the green wires?

[harborman]

Mine has been disconnected.

Disconnected = high octane



Connected = Low grade fuel.



Stated by Landseer (asked same question)



Edit: Just looked at a chart showing fuel rating for different 928s, and according to that, your car should be running 95 octane, so maybe you should try and connect the green wires?

[porken]

95 EU/RON = 89 USA/AKI - this is likely the recommended octane for the ROW 32V, which had lower compression pistons.

Super (92 USA/AKI=98 EU/RON) is called for in the manual for USA versions, but I never had any trouble running Plus/89 with the stock chips.

The EZF 'octane loop' (green wires) shorts the Temp I/air temp sensor, making the EZF think the airbox is very hot. It retards 3° at higher loads/rpm.

The LH 'octane loop' (brown wires) is an input to the processor. It just changes the O2 sensor swing pattern slightly. (Doesn't go as far lean, IIRC.)