Jaguar XJ 6 - 3.2 Auto-1997 P Reg. When the engine is cold very slight engine miss at idling speed which goes off atfer 2-3 miles Diagnostic test done. Changed one fuel injector and full service carried out but the problem still exists

2005 Jaguar XJ-Series
Tim, Will have to have it scanned to retrieve trouble codes, to be able to diagnose why it is going into limp.

If your car has a distributor cap then condensation got in it and must be dried off with a paper towel. you must loosen the cap, usually has 2 screws or clips.

Check your idle sensor solenoid...

I think you mean the engine stalls or cuts out at Idle/30/60 mph.
More info wanted,as first is it a Man/or Auto ,what engine have you got 6 or v8??? When last servised by who,How many miles on the clock,dose it smoke when driving or starting ,are the revs ok on idle ,,about what temp dose it run at the 30/60 mph etc etc???
PLEASE send all info, ..
Ron.

not normal. bad spark plug wires they may be gapping or jumping spark. also maybe coil pack is doing same thing.

the gas gauge is not related, that would be a defective gas gauge sending unit in the gas tank, the check engine light indicates that one of around 200 poss faults has occured in the electronic engine controls, you will need to have the OBD 2 engine control system tested for the fualt code that is stored when the light is turned on.

with great difficulty,tell me about it ------undo radiator mounts and jiggle it over a bit ,the support brackets on mine were pop rivited to chassis .remove the top bar that goes over the top of the rad first though.

have you tried a new coolant sensor?it is poss it is telling the ecu its still cold so its chucking more fuel through. also get a block tester and test cylinder head

Since this is an intermittent problem, first try to determine if the problem arises due to one of these many intermittent problems:

* Vehicle vibration
* Heat sensitive
* Freezing
* Water intrusion
* Electrical load
* Cold or hot start up

If you can't isolate the cause of the intermittent problem, you can try adjusting the Idle Speed/Ignition Timing/Idle Mixture Ratio:

Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment

PREPARATION
1) Make sure that the following parts are in good order.

* Battery
* Ignition system
* Engine oil and coolant levels
* Fuses
* ECM harness connector
* Vacuum hoses
* Air intake system
* (Oil filler cap, oil level gauge, etc.)
* Fuel pressure
* Engine compression
* EGR valve operation (If so equipped)
* Throttle valve
* Evaporative emission system

2) On air conditioner equipped models, checks should be carried out while the air conditioner is OFF.
3) On automatic transmission equipped models, when checking idle rpm, ignition timing and mixture ratio,
checks should be carried out while shift lever is in “N” position.
4) When measuring “CO” percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5) Turn off headlamps, heater blower, rear defogger.
6) Keep front wheels pointed straight ahead.
7) Make the check after the cooling fan has stopped.

INSPECTION PROCEDURE

1 INSPECTION START
1. Visually check the following:
I Air cleaner clogging
I Hoses and ducts for leaks
I EGR valve operation (If so equipped)
I Electrical connectors
I Gasket
I Throttle valve and throttle position sensor operation
2. Start engine and warm it up until engine coolant temperature indicator points to the middle of gauge.
Ensure engine stays below 1,000 rpm.
3. Open engine hood and run engine at about 2,000 rpm for about 2 minutes under no-load.
4. Perform diagnostic test mode II (Self-diagnostic results).
OK or NG
OK ' GO TO 2.
NG ' 1. Repair or replace components as necessary.
2. GO TO 2.

2 CHECK IGNITION TIMING
1. Run engine at about 2,000 rpm for about 2 minutes under no-load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no-load, then run engine at idle speed.
3. Turn off engine and disconnect throttle position sensor harness connector.
4. Start and rev engine (2,000 - 3,000 rpm) two or three times under no-load, then run at idle speed.
5. Check ignition timing with a timing light.
15°±2° BTDC (in “P” or “N” position)
OK or NG
OK ' GO TO 4.
NG ' GO TO 3.

3 ADJUST IGNITION TIMING
1. Adjust ignition timing by turning distributor after loosening securing bolts.
2. Turn off engine and connect throttle position sensor harness connector to throttle position sensor.
' GO TO 2.


4 CHECK BASE IDLE SPEED
1. Check idle speed.
700±50 rpm (in “P” or “N” position)
OK or NG
OK ' GO TO 6.
NG ' GO TO 5.

5 ADJUST BASE IDLE SPEED
1. Rev engine (2,000 to 3,000 rpm) 2 or 3 times under no-load then run engine at idle speed.
2. Adjust idle speed by turning idle speed adjusting screw.
700±50 rpm (in “P” or “N” position)
' GO TO 6.

6 CHECK TARGET IDLE SPEED
1. Turn off engine and connect throttle position sensor harness connector.
2. Start and rev engine (2,000 to 3,000 rpm) 2 or 3 times under no-load then run at idle speed.
3. Check idle speed.
750±50 rpm (in “P” or “N” position)
OK or NG
OK ' GO TO 9.
NG ' GO TO 7.

7 DETECT MALFUNCTIONING PART
Check the following.
1. Check IACV-AAC valve and replace if necessary.
2. Check IACV-AAC valve harness and repair if necessary.
3. Check ECM function by substituting another known good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
' GO TO 9.

9 CHECK FRONT HEATED OXYGEN SENSOR LH SIGNAL
1. Run engine at about 2,000 rpm for about 2 minutes under no-load.
2. Set “Left bank front heated oxygen sensor monitor” in the Diagnostic Test Mode II.
3. Make sure that MIL goes on more than 5 times during 10 seconds at 2,000 rpm.
OK or NG
OK ' GO TO 12.
NG (MIL does not blink.) ' GO TO 17.
NG (MIL blinks less than 5 times.)
' 1. Replace front heated oxygen sensor LH.
2. GO TO 10.


10 CHECK FRONT HEATED OXYGEN SENSOR LH SIGNAL
1. Warm engine to normal operating temperature.
2. Run engine at approx. 2000 rpm for approx. 2 minutes under no-load.
3. Set “Left bank front heated oxygen sensor monitor” in the Diagnostic Test Mode II.
4. Make sure that MIL goes on more than 5 times during 10 seconds at 2,000 rpm.
OK or NG
OK ' GO TO 13.
NG ' GO TO 11.

11 DETECT MALFUNCTIONING PART
Check the following.
1. Check fuel pressure regulator.
2. Check mass air flow sensor and its circuit.
3. Check injector and its circuit.
Clean or replace if necessary.
4. Check engine coolant temperature sensor and its circuit.
5. Check ECM function by substituting another known good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
' GO TO 2.


13 CHECK FRONT HEATED OXYGEN SENSOR RH SIGNAL
1. Set “Right bank front heated oxygen sensor monitor” in the Diagnostic Test Mode II.
2. Make sure that MIL goes on more than 5 times during 10 seconds at 2,000 rpm.
OK or NG
OK ' INSPECTION END
NG (MIL does not blink.) ' GO TO 16.
NG (MIL blinks less than 5 times.)
' 1. Replace front heated oxygen sensor RH.
2. GO TO 14.


14 CHECK FRONT HEATED OXYGEN SENSOR RH SIGNAL
1. Warm engine to normal operating temperature.
2. Run engine at approx. 2000 rpm for approx. 2 minutes under no-load.
3. Set “Right bank front heated oxygen sensor monitor” in the Diagnostic Test Mode II.
4. Make sure that MIL goes on more than 5 times during 10 seconds at 2,000 rpm.
OK or NG
OK ' INSPECTION END
NG ' GO TO 15.

15 DETECT MALFUNCTIONING PART
Check the following.
1. Check fuel pressure regulator.
2. Check mass air flow sensor and its circuit.
3. Check injector and its circuit. Clean or replace if necessary.
4. Check engine coolant temperature sensor and its circuit.
5. Check ECM function by substituting another known good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
' GO TO 2.
16 CHECK FRONT HEATED OXYGEN SENSOR RH HARNESS
1. Turn off engine and disconnect battery ground cable.
2. Disconnect ECM harness connector.
3. Disconnect front heated oxygen sensor RH harness connector.
4. Check harness continuity between ECM terminal 50 and front heated oxygen sensor RH harness connector.
Continuity should exist.
OK or NG
OK ' 1. Connect ECM harness connector.
2. GO TO 18.
NG ' 1. Repair or replace harness.
2. GO TO 9.

17 CHECK FRONT HEATED OXYGEN SENSOR LH HARNESS
1. Turn off engine and disconnect battery ground cable.
2. Disconnect ECM harness connector.
3. Disconnect front heated oxygen sensor LH harness connector.
4. Check harness continuity between ECM terminal 51 and front heated oxygen sensor LH harness connector.
Continuity should exist.
OK or NG
OK ' 1. Connect ECM harness connector.
2. GO TO 18.
NG ' 1. Repair or replace harness.
2. GO TO 9.

18 PREPARATION FOR “CO” % CHECK
1. Disconnect engine coolant temperature sensor harness connector.
2. Connect a resistor (4.4 kW) between terminals of engine coolant temperature sensor harness connector.
' GO TO 19.

19 CHECK “CO” %
1. Start engine and warm it up until engine coolant temperature indicator points to the middle of gauge.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no-load, then run engine at idle speed.
3. Check “CO” %.
Idle CO: 1.5 - 9%
After checking CO%,
a. Disconnect the resistor from terminals of engine coolant temperature sensor.
b. Connect engine coolant temperature sensor harness connector to engine coolant temperature sensor.
OK or NG
OK ' 1. Replace front heated oxygen sensor LH.
2. GO TO 10.
NG ' GO TO 20.

20 DETECT MALFUNCTIONING PART
Check the following.
1. Connect front heated oxygen sensor harness connectors to front heated oxygen sensors.
2. Check fuel pressure regulator.
3. Check mass air flow sensor and its circuit.
4. Check injector and its circuit.
Clean or replace if necessary.
5. Check engine coolant temperature sensor and its circuit.
6. Check ECM function by substituting another known good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
' GO TO 2.

HI
firstly what is the number of diagnostic code?? (P0???)
the (IAC)idle air control motor locate in the engine near the intake manifold it have a 6 pin connector:-
the 2 & 5 is 12 volt supply from fuse box
the 1,3,4&6 is from (ECU) engine control unit
it function is control the idle speed of engine

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