Range Rover (LH) V8-3.5L (1987)
Ignition Rotor: Technical Service Bulletins
Distributor Dwell - Erratic Readings
NO. 86/05/94/US
DATE: 07/29/94
MODEL
Range Rover
AFFECTED VEHICLES
All Range Rover prior to LH 639964
SUBJECT
Erratic Distributor Dwell
DETAIL
During Distributor Dwell Checks with a dwell meter, you may observe erratic ignition dwell readings at engine speeds of between 1000 and 3000 rpm,
most likely to occur between 1500 and 2500 rpm.
The erratic dwell is generally an extreme and downward change in the dwell period. Radio frequency noise generated from the tip of the ignition rotor
interferes with the coil current control circuitry in the ignition module which results in erratic dwell.
This symptom is cured by installing a new design rotor which has a coating of silicon on the rotor tip. The new rotor was introduced from the listed VIN
number and can be fitted to previous vehicles.
ACTION REQUIRED
Upon evidence of erratic dwell install the new rotor. DO NOT REPLACE THE IGNITION MODULE IF ERRATIC DWELL IS EVIDENT.
PARTS INFORMATION
STC 1857 Rotor replaces RTC 6629
PROCEDURE
Refer to section 86 of the workshop manual, repair page 59, steps 4 and 5 fitting instructions.
Note
The silicon can be visibly seen on the tip of the rotor.
Reference E-Mail # 19-94/01
Illustration
WARRANTY
Normal warranty policy and procedures apply
COMP. CODE
7A6U
SR0
86.35.16 Rotor renew 00.20 hour