Date of issue 10/01 Bulletin Number 303-47 Page 1 of 1
10/01V8 XJ Series/XK
1997-98 MY XK8 Range
1998 MY V8 XJ Series
1998-99 MY XJR
Hesitation, Surging, Detonation,
Poor Throttle Response/Acceleration –
Diagnostic Flowcharts – AJ 26 Engines
This Technical Bulletin provides diagnostic information relating to various engine drivability
concerns such as hesitation, backfiring, surging, knocking, poor throttle response, and cruise
control inhibited. The diagnosis is organized by the symptoms that the customer experiences.
Before using the guide, check the Symptom Matrix (next page) for the diagnostic flowchart
sequence. For example, if the cruise control is inhibited or disabled, work through flowcharts
P28, P30 and P27.
Following the flowcharts in the sequence identified will help rectify any concerns while
optimizing the utilization of workshop time.
Note: When working on any vehicle ensure that exposed paintwork is
protected with the appropriate fender protection covers.
RELAY CODES AND DATE STAMPS
Relay date codes come in two forms:
• Relays prior to December 1998 have the format: Letter – Number – Letter i.e. R6 K1
• Relays after December 1998 have the format: Number – Letter – Letter i.e. 2AB
All date codes are printed in white on the top face of the relay, adjacent to the part number.
Warning: Working on the fuel system can result in fuel vapor being
emitted into the atmosphere. Fuel vapor is extremely flammable; hence great
care should be taken when working on the fuel system.
Do not smoke in the working area and ensure that there is a CO2 fire
extinguisher close by. The working area must be well ventilated and
extraction equipment used when appropriate. When emptying fuel, use
suitable fireproof equipment and an authorized explosion-proof container.