E30 318i M40: Bosch injectors and tips - checking condition

Next on the agenda to find the culprit of the rough running and stalling idle was to examine the injector condition and the plastic tips. The injector bodies are quite rusty and corroded so they could well be the original set, but on closer inspection the tips are fine and they look to be in pretty good condition, so onwards.

To inspect the injectors the lower inlet manifold will need to be removed, which involves de-plumbing the fuel lines and some of the water hoses. 

BMW Bosch Fuel Injection System Trouble-Shooting Guide

SYMPTOM:	PROBABLE CAUSE:
No cold start	Fuel-pump fault or clogged fuel-filter
	Additional air-valve not opening correctly
	Start-valve not opening correctly
	Leak in fuel system
	Throttle-valve plate not opening correctly
	Temp.-sensor fault
	Diode-relay fault
Poor hot start	As above then:
	Leaking / faulty injector
	Heat/time switch fault
Poor idle	Baffle-plate stop wrongly adjusted
	Leak in Vacuum-system
	Fuel-filter clogged
	Mixture-adjustment incorrect
Backfire from engine	Weak fuel mixture
	Fuel pressure too low
	Starter-valve leaking
Engine runs on after shut-off	Leaking / faulty injector
	Stiff/stuck baffle-plate
	Stiff/stuck control-plunger
Excessive fuel consumption	Control pressure too low
	Starter-valve leaking
	Leak in fuel-system
	Fuel mixture too rich
	Heat/time switch fault
Idle-speed too high	Control pressure incorrect
	Additional air-valve stuck open
	Baffle-plate stop wrongly adjusted

Detailed maintenance guide / diagrams in this post [L-Jetronic] - https://www.beemerlab.org/2020/03/bmw-bosch-l-jetronic-fuel-injection.html

Bosch K-Jetronic injection-system overview / diagram here - https://www.beemerlab.org/2019/11/e21e12e28-bosch-k-jetronic-fuel.html

Bosch L-Jetronic injection-system overview / diagram here - https://www.beemerlab.org/2019/11/e30e28e34-bosch-l-jetronic-fuel.html

BMW Bosch L-Jetronic Fuel Injection - Strip-Down / Maintenance Guide + Diagrams [E30, E21, E28]

Throttle Housing:
1. Disconnect the cables (1, 2 or 3) as applicable - Fig. 1.
2. Pull off the vacuum hoses, the coolant hoses (1 and 2) - allowing the coolant to drain - and the air hoses (3 and 4) from the throttle housing - Fig. 2.
3.Remove the vacuum hoses (1 and 2), and the air hose (3) and pull off the multi-pin plug (4) - Fig. 3.
4. Remove the fixing nuts and take off the throttle housing. Do not separate the throttle switch from the housing, as a special gauge will be required to adjust it when refitting.
5. Refitting is a reversal of removal. Use a new gasket and bleed the cooling system.

Throttle Vacuum Control:
1. Pull off the hose (1), release the nut (2) and remove the vacuum control (3) - Fig. 4.
2. When refitting, adjust dimension (B) to between 32.8mm and 33.2mm (1.291" and 1.307") using screw (4).
3. Adjust dimension (A) to between 2.6mm and 3.0mm (0.102" and 0.118") using screw (2) - Fig. 5.

Control Unit:
1. Open the glove compartment and pull the pins from the retaining straps.
2. Remove the screws and place the glovebox cover to one side.
3. Depress the retainer (1) and pull out the multi-pin plug (2) - Fig. 6. Remove the control unit.

Air-flow Sensor:
1. Release the clamp and pull the duct from the air-flow sensor.
2. Disconnect the multi-pin plug, unscrew the fixing nuts and withdraw the sensor.
3. Refitting is a reversal of removal. Renew the seal if necessary.

Temperature Time Switch:
1. Pull off the plug, then unscrew and remove the switch.
2. Refit the switch using a new sealing washer.

Coolant Temperature Sensor:
1. Pull off the plug and unscrew the sensor. Refit using a new sealing washer.

Cold Start Valve:
1. Pull off the plug (1) and disconnect the fuel line (2) - Fig. 7.
2. Unscrew the mounting bolts (3 and 4) and withdraw the valve.
3. Use new seal when refitting.

Fuel Injectors:
1. Unscrew the four injection tube bolts and push the tube upwards until the fuel injectors have cleared the guide in the intake manifold.
2. Pull off the plug (1) and take out the circlip (2) - Fig. 8.
3. Take off the fuel injector.
4. Refitting is a reversal of removal; use new O-ring seals.

Throttle Shaft Return Springs:
1. Disconnect the throttle, kick-down and cruise-control cables. (The latter two where applicable.)
2. Remove the retainer (1), washer (2) and disconnect the linkage (3) on the lever (4).
3. Raise the lever and turn it to relieve the spring tension.
4. Remove the lever.
5. Remove the spring.
6. Disconnect the spring (1) and unscrew the nut (2) - Fig. 9.
7. Remove the washer (1) and lever (2) - Fig. 10.
8. Remove the sleeve (1) and spring (2) - Fig. 11. - also the wave washer.
9. Reassemble in the reverse order to dismantling and adjust in the following way - Pull off the tamperproof lock (1) and loosen the screw (2) until the lever (3) no longer rests on the screw - Fig. 12.
10. Place a finger on the lever and tighten the screw until the lever just begins to move. Turn the screw a quarter-turn more and refit the tamperproof lock.
11. Adjust the throttle, kick-down and cruise-control cables (where applicable).

Injection-system trouble-shooting guide here - https://www.beemerlab.org/2020/12/bmw-bosch-fuel-injection-system-trouble.html

Bosch L-Jetronic injection-system overview / diagram here - https://www.beemerlab.org/2019/11/e30e28e34-bosch-l-jetronic-fuel.html

BMW Common Engine/Injection Error Codes / Fault Codes List 2D00-2FB7 + CD87-CDAC [E46, E39 etc.]

2711-273F, 2740-2772, 2773-279F, 27A0-27FF, 280A-29FF, 2A01-2CFF, 2D00-2FB7, CD87-CDAC,

2D00 spring-check throttle-valve-actuator
closing spring
2D01 spring-check throttle-valve-actuator
opening spring
2D02 error emergency air setpoint
2D03 Abort DV-adaption because of enviroment
2D04 throttle valve adaption
2D05 Abort at UMA-repeat learning
2D08 parts exchange without adaption
2D0F Hot film air mass meter
2D10 Plausibility HFM
2D11 Plausibility, mass flow Lambda sensor
2D12 Plausibility, mass flow Lambda sensor
BAnk2
2D19 PWG-movement
2D1A accelarator potentiometer
2D1B Pedal-travel Poti1
2D1C Pedal-travel Poti2
2D28 Diff. pressure sensor suction tube
2D29 Plausibility diff. pressure sensor
2D32 Plausibility pressure sensor intake tube
2D6E moment monitoring level 2
2D6F Load sensor monitoring
2D70 Control unit monitoring group A
2D71 Control unit monitoring group B
2D72 Control unit monitoring group C
2D73 fuel pressure sensor
2D74 funktion monitoring: Lambda Plausibility
2D75 engine speed monitoring
2D76 pedal encoder monitoring (level2)
2D78 Control air mass flow adjustment
2DB4 interface MFL
2DBF CAN ACC signal failure
2DC8 CAN- Timeout EGS
2DCA CAN timeout EGS
2DCB CAN SSG signal failure
2DCF CAN- Timeout instrument combination
2DD6 CAN- Timeout ASC/DSC
2DD7 CAN timeout DSG SG
2DD8 active front steering torque
2DD9 CAN ARS signal failure
2DDA CAN CAS signal failure
2DDB CAN IHKA signal failure
2DDC CAN SZL signal failure
2DDD CAN-Timeout VVT-Control unit
2DDE VVT-CAN-communication
2DDF VVT-CAN-communication (bank2)
2DE6 CAN-Timeout DME-Control unit
2DEB power management network failure
2DEC power management
2DED Powermanagement: quiescent current
violation
2E24 spark coil cylinder 1 in 1. ignition
sequence
2E25 spark coil cylinder 2 in 4. ignition
sequence
2E26 spark coil cylinder 3 in 2. ignition
sequence
2E27 spark coil cylinder 4 in 3. ignition
sequence
2E30 injection valve cylinder 1 in 1. cylinder
sequence
2E31 injection valve cylinder 2 in 4. cylinder
sequence
2E32 injection valve cylinder 3 in 2. cylinder
sequence
2E33 injection valve cylinder 4 in 3. cylinder
sequence
2E68 Knock sensor 1
2E69 knock sensor2 (Bank1)
2E6A Knock sensor 3
2E6B Knock sensor 4
2E7C BSD wire failure
2E86 Electrical water pump
2E8B IBS communication
2E8C IBS general error
2E8D IBS plausibility
2E95 generator communication
2E97 CDKDGEN/CDKGEN - BSD generator
2E9F Failure oil quality sensor
2EA0 Oil status sensor
2EB8 BSD-message from IBS not existent
2EBC BSD message from oil sensor missing
2EBD BSD message from generator missing
2EBE BSD message from generator missing
2EE0 Temperature sensor engine cooling liquid
2EEA Temp. sensor coolant temperature
2EF4 Thermostat characteristic diagram cooling,
mechanical
2EF5 Thermostat characteristic diagram cooling,
activation
2EF6 characteristic diagram thermostat
2EFE engine blower
2F08 Intake air temperature
2F0D Control controlled airflow
2F12 Air conditioner compressor control
2F17 Forced switched EGS
2F1C oil temperature sensor
2F21 engine controller, power reduction
2F44 EWS3.3 manipulation protection
2F45 EWS3.3 Interface DME-EWS
2F46 EWS3.3 Random-code storing
2F4E Vehicle speed
2F50 failure at speed-display kombi
2F58 Control starter automatic
2F59 Input starter automatic
2F5A Start automatic control
2F62 Switch brakes
2F67 Switch clutch
2F6C Control exhaust flap
2F71 E-Box blower
2F76 Ambient-pressure sensor
2F7B oil pressure switch
2F80 error CAN / relative timer
2F85 DME- Temperature
2F8A Battery Voltage
2F94 fuelpump relay
2F99 Ambient temperature
2F9E Thermical oillevel sensor
2FA3 HO-proc.failure, coding missing
2FB2 suction jet pump for brake force amplifier
2FB7 electr. under pressure pump for brake
booster

CD87 PT - CAN bus off
CD8B Local CAN Bus Off
CD9B status vehicle-mode
CDA1 angle of steering wheel
CDA2 powermanagement battery voltage
CDA3 powermanagement charge voltage
CDA7 status gear reverse
CDAA control crash-switch-off EKP
CDAC status water valve

E21/E12/E28: Bosch K-Jetronic Fuel Injection System Diagram / Explanation

Two types of fuel injection system are fitted. E21 3er 323i models are equipped with the Bosch K-Jetronic system, whereas E30 3er 320i and 325i models are fitted with the Bosch L-Jetronic system. This article covers K-Jetronic injection for E21 models, also injected E12 and early E28 5er. For L-Jetronic in E30 models, also later injected E28 5er, see THIS ARTICLE.

K-Jetronic Operation:
Fuel is drawn from the fuel tank by an electrically-operated pump and is then fed, via a pressure reservoir and filter unit, to the fuel distributor-unit. The fuel is then pumped direct to the fuel injectors which are located near the inlet valves, but mounted in four induction-manifold branches. The system is continuous acting type and the amount of fuel admitted to the injectors, by the fuel distributor, is governed by a pivoting baffle-plate mounted in the air-intake. Air drawn into the engine lifts the baffle-plate and this action moves a metering shuffle-valve in the fuel distributor. The ratio of air to fuel is thus controlled to a fine degree. After the mixture is drawn into the cylinder, the normal four-stroke combustion cycle takes place.

The fuel is maintained at a constant pressure by a pressure-regulator incorporated into the fuel distributor-unit, excess fuel being diverted through a return-line back to the fuel tank.

For cold starting, a solenoid valve injects fuel into the air-intake for a period determined by the coolant temperature. In addition, a temperature sensitive (warm-up) regulator, working in conjunction with an additional air slide-valve, is connected to the fuel distributor-unit and has the effect of increasing the amount of fuel delivered by the injectors. Later models are fitted with a throttle bypass-valve in place of the additional air slide-valve. On some specific versions this valve is coolant-heated.

A normal type throttle butterfly-valve, mounted between the baffle-plate and the cylinders, is connected to the accelerator pedal linkage. These constant flow injection systems work in a similar manner to a carburettor, vaporising fuel in the inlet-manifold and metering it into the engine.