Eng Speed Fluctuation Moderate Speed Closed THOTTLE (19/04/97/NAS)
Publication date: 1997-06-20Reference number: 19/04/97/NAS
ENG SPEED FLUCTUATION MODERATE SPEED CLOSED THOTTLE
TECHNICAL SERVICE BULLETIN
ENGINE SPEED FLUCTUATION AT MODERATE SPEED CLOSED THROTTLE
Model(s): 1997 Land Rover Discovery (LJ)
Reference: WSM Section 19, TIB 19/08/96/US
Issue: 2
Group: Fuel System
Bulletin Number: 19/04/97/NAS
Date: June 20, 1997
AFFECTED VEHICLE RANGE
Discovery (LJ) 1997 MY advanced EVAPS equipped:
VIN up to VA727076 Automatic.
VIN up to VA726789 Manual.
VIN up to VA558898 Manual and Automatic.
SITUATION
IDLE FLUCTUATES DURING MODERATE SPEED CLOSED THROTTLE OPERATION
There have been reports of engine flare or surge when the vehicle is decelerating. The engine speed may fluctuate between 1200 and 1600 rpm (up to 400 rpm total fluctuation) when the throttle is closed and the vehicle speed is between 35 and 50 mph (56-80 kph.). This may occur in GEMS equipped, Advanced EVAPS vehicles in the above VIN ranges.
RESOLUTION
REPLACE PROM
Upon customer complaint only install a new PROM set which has been developed to eliminate the problem. Replace the PROM set using established Operation Pride procedures. (TIB 19/08/96/US)
PARTS INFORMATION
| Part Number | Description |
|---|---|
| PRM9640 | PROM - Automatic |
| PRM9641 | PROM - Manual |
| LRNASTATK | Anti-Static Mat |
REPAIR PROCEDURE
REPLACE PROM
- Call the GEMS help line.
- The help line will issue a new specification PROM set that will eliminate the concern.
- Use procedures outlined in earlier phases of Operation Pride to replace PROM set. (TIB 19/08/96/US)
- Following installation of the PROM set, start and warm up the vehicle from full cold to hot at idle, in Drive with the park brake applied. This will adapt the engine management IACV system and minimize any noticeable changes to the customer upon return of the vehicle.
WARRANTY INFORMATION
18.30.89/26: Fill out DPR and FAX to LRNA, Replace GEMS PROM
Time: 0.50 hr.
Comp Code: 7G1A
Normal warranty policy and procedures apply.