K-Jetronic: Troubleshooting Symptoms

From: Subject: K-Jetronic: Troubleshooting Symptoms Date: Sun, 2 Jan 2005 01:09:13 +0100 MIME-Version: 1.0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.forparts.com/techbosKjectronic.htm X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 K-Jetronic: Troubleshooting Symptoms Olympus =20 Imported Auto Parts=20 Corporation &n= bsp; &nb= sp; &nbs= p;=20 Presented by Bosch=20

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What's=20 = New

K-Jetronic:=20 Troubleshooting Symptoms

K-Jetronic = is a mechanical=20 system: the fuel is continuously metered in proportion to the = quantity of=20 air drawn in by the engine. The K-Jetronic system was installed as = Original Equipment in series production vehicles in the years 1973 = through=20 1995. Since then, the K-Jetronic system has been only of = significance for=20 repairs and maintenance.

Symptoms:

Engine = does not=20 start/starts hard when cold

Engine = does not=20 start/starts hard when warm

Irregular = idle=20 during warm-up

Irregular idle=20 with warm engine

Engine = will not=20 accelerate, backfires

Engine = backfires=20 under load

Poor=20 Performance

Engine = runs=20 on

Fuel = consumption too=20 high

Driving = performance=20 unsatisfactory

CO = concentration=20 at idle too high

CO = concentration at=20 idle too low

Idle = speed=20 cannot be adjusted (too high)

Engine starts=20 but immediately dies

Symptom: Engine = does not=20 start/starts hard when cold

Cause	Remedy
Sensor = plate and/or=20 plunger not moving freely	Check = for free=20 movement
Auxiliary air valve=20 does not open	Check = valve for=20 correct function
Electric fuel pump=20 not operating	Check = pump fuse,=20 pump relay and pump
Cold = start system=20 defective	Check = cold start=20 system
Therm-time switch=20 defective	Test = thermo-time=20 switch
"Cold" = control=20 pressure outside tolerance	Test=20 pressure
Injector leaking,=20 opening pressure low	Check = injectors on=20 tester
Injected fuel=20 quantities unequal	Check = for equal fuel=20 quantities
Basic = idle setting=20 incorrect	Check = and adjust CO=20 level

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Symptom: Engine does not start/starts hard = when=20 warm

Cause	Remedy
Leaks in=20 air intake system (false air)	Check air=20 system for leaks
Sensor=20 plate and/or plunger not moving freely	Check for=20 free movement
Air flow=20 sensor plate stop incorrectly set	Check and=20 reset
Electric=20 fuel pump not operating	Check pump=20 fuse, pump relay and pump
"Warm"=20 control pressure too high	Test=20 pressure
Fuel=20 system leakage	Inspect=20 fuel system for leaks
Injector=20 leaking, opening pressure low	Check=20 injectors on tester
Injected=20 fuel quantities unequal	Check for=20 equal fuel quantities
Basic idle=20 setting incorrect	Check and=20 adjust CO level

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Symptom: Irregular idle during=20 warm-up

Cause	Remedy
Leaks = in air intake=20 system (false air)	Check = air system for=20 leaks
Auxiliary air valve=20 does not open	Check = valve for=20 correct function
Cold = start valve=20 leaking	Check = cold start=20 valve
"Cold" = control=20 pressure outside tolerance	Test=20 pressure
Injector leaking,=20 opening pressure low	Check = injectors on=20 tester
Injected fuel=20 quantities unequal	Check = for equal fuel=20 quantities
Basic = idle setting=20 incorrect	Check = and adjust CO=20 level
Lambda = control=20 system not functioning correctly	Check = Lambda control=20 system

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Symptom: Irregular idle with warm=20 engine

Cause	Remedy
Leaks = in air intake=20 system (false air)	Check = air system for=20 leaks
Sensor = plate and/or=20 plunger not moving freely	Check = for free=20 movement
Cold = start valve=20 leaking	Check = cold start=20 valve
"Warm" = control=20 pressure too high	Test=20 pressure
"Warm" = control=20 pressure too low	Test=20 pressure
Injector leaking,=20 opening pressure low	Check = injectors on=20 tester
Injected fuel=20 quantities unequal	Check = for equal fuel=20 quantities
Basic = idle setting=20 incorrect	Check = and adjust CO=20 level
Lambda = control=20 system not functioning correctly	Check = Lambda control=20 system

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Symptom: Engine will not accelerate,=20 backfires

Cause

Remedy

Leaks in air intake system (false=20 air)	Check air system for leaks
Sensor plate and/or plunger not = moving=20 freely	Check for free movement
"Warm" control pressure too high	Test pressure
"Warm" control pressure too low	Test pressure
Basic idle setting incorrect	Check and adjust CO level
Lambda control system not functioning = correctly	Check Lambda control=20 system

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Symptom: Engine = backfires under=20 load

Cause

Remedy

Sensor plate and/or plunger not = moving=20 freely	Check for free = movement
Electric fuel pump not = operating	Check pump fuse, pump relay and=20 pump
"Warm" control pressure too = high	Test pressure
Primary system pressure out of=20 tolerance	Test pressure and adjust with=20 shim
Injector leaking, opening pressure=20 low	Check injectors on=20 tester

top

Symptom: = Poor=20 Performance

Cause

Remedy

Leaks in air intake system (false=20 air)	Check air system for = leaks
Sensor plate and/or plunger not = moving=20 freely	Check for free = movement
"Warm" control pressure too = high	Test pressure
"Warm" control pressure too = low	Test pressure
Primary system pressure out of=20 tolerance	Test pressure and adjust with=20 shim
Injected fuel quantities = unequal	Check for equal fuel = quantities
Throttle butterfly does not open=20 completely	Check butterfly and stops in = throttle=20 venturi
Lambda control system not = functioning=20 correctly	Check Lambda control=20 system

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Symptom: = Engine runs=20 on

Cause

Remedy

Sensor plate and/or plunger not = moving=20 freely	Check for free = movement
Air flow sensor plate stop = incorrectly=20 set	Check and reset
Cold start valve = leaking	Check cold start = valve
Injector leaking, opening pressure=20 low	Check injectors on = tester
Basic idle setting = incorrect	Check and adjust CO=20 level

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Symptom: = Fuel consumption=20 too high

Cause

Remedy

Cold start valve = leaking	Check cold start = valve
"Warm" control pressure too = low	Test pressure
Basic idle setting = incorrect	Check and adjust CO = level
Lambda control system not = functioning=20 correctly	Check Lambda control=20 system

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Symptom: = Driving=20 performance unsatisfactory

Cause

Remedy

Leaks in air intake system (false=20 air)	Check air system for = leaks
Sensor plate and/or plunger not = moving=20 freely	Check for free = movement
Excessive fuel delivery to control circuit	Check fuel delivery
"Warm" control pressure too high	Test pressure
"Warm" control pressure too low	Test pressure
Primary system pressure out of tolerance	Test pressure and adjust with shim
Basic idle setting incorrect	Check and adjust CO level
Lambda control system not functioning = correctly	Check Lambda control=20 system

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Symptom: CO = concentration at idle=20 too high

Cause

Remedy

Sensor plate and/or plunger not moving = freely	Check for free movement
Cold start valve leaking	Check cold start valve
"Warm" control pressure too high	Test pressure
Basic idle setting incorrect	Check and adjust CO level
Lambda control system not functioning = correctly	Check Lambda control=20 system

top

Symptom: CO concentration at idle too low

Cause	Remedy
Leaks in air intake system (false air)	Check air system for leaks
Sensor plate and/or plunger not moving freely	Check for free movement
Basic idle setting incorrect	Check and adjust CO level
Lambda control system not functioning = correctly	Check Lambda control=20 system

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Symptom: Idle speed = cannot be=20 adjusted (too high)

Cause	Remedy
Auxiliary air valve does not close	Check valve for correction = function

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Symptom: Engine = starts but=20 immediately dies

Cause	Remedy
Electric fuel pump not operating	Check pump fuse, pump relay and pump
Excessive fuel delivery to control circuit	Check fuel delivery
"Warm" control pressure too high	Test pressure
"Warm" control pressure too low	Test pressure
Primary system pressure out of tolerance	Test pressure and adjust with=20 shim

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Check our online catalogs for other parts = for your=20 vehicle