This material is drawn from a technical bulletin specifically regarding engine idling problems on the Rover SD1 Vitesse with Twin Throttle Plenum, but much of the program may be applied laterally to the Single Plenum installation on both the Earlier Vitesse and Efi Vanden Plas.
It addresses a common fault known as “Idle Speed Hang-up”. Excess friction in the assembly is a killer caused variously by damage, misalignment, contamination and maladjustment. Blocked airways and air leaks are also a concern. Here is an action program to resolve the problem.
Read or download the article in PDF format from here: (170kb)
However, it covers only a small part of the complete Efi system. If there are other fuel injection problems requiring attention, they can be addressed using my Testing and Adjustment Program:
Engine Idling Problems on Rover SD1 Vitesse
Click Here to Read or Download the PDF Article - or the below links
Snippet - Image shows substitute throttle pot as fitted to my TP Vitesse using customised plate to replace the original Rover parts. It has a rotary deflection of 105 deg versus 90 deg for the original, so the maximum voltage achieved at full throttle is appprox 4.3 X 90 / 105 = 3.7 volts.
This is not a problem and performance of the SD1 Efi system is unaffected under normal conditions unless for some reason full throttle rotation is other-wise restricted by a mechanical fault. Buy replacement unit from Radiospares Tel 01536 204555, P/N 319-310, Rotary Position Sensor, 5000 ohm. LATEST WEB-LINK - Here:
Much more in theThrottle Pot PDF here:
Substitute Throttle Pot