Engine Controls - On-Vehicle Adjustments: Other

Checking Basic Charging Pressure - On-Road (B205L/R & B235R)

Position Pressure Gauge (83 93 514) vertically to reduce the risk of it giving incorrect readings. (Scheme 1)
Connect the pressure measuring equipment to the intake manifold. (Scheme 1)
Accelerate at full throttle in 3rd gear from an engine speed below 1500 RPM. When the engine speed approaches 3000 RPM, depress the brake pedal while holding the accelerator down to produce a maximum load at 3000 RPM. Note the reading on the charge pressure gauge. If the charge pressure exceeds the tolerance limits, refer to «ADJUSTING BASIC CHARGING PRESSURE»(ref-132873-S11434072772003080400000).
Remove the pressure gauge and adjust the boost pressure.

Scheme 1

Adjusting Boost Pressure Control Valve (B205L/R & B235R)

Remove the bypass pipe with valve.
Remove the exhaust manifold heat shield. The heat shield is fastened with a nut and two clips underneath. (Scheme 2)
Remove the circlip from the operating arm, using Circlip Tool (83 94 538). (Scheme 2)
Hold the pushrod with pliers and undo the lock nut. (Scheme 3)
Hold the operating arm and detach the pushrod. Secure the arm. Otherwise, the operating arm may "jump over". (Scheme 3)
Move the operating arm on the boost pressure control valve towards "Closed" and adjust the end piece so that the pushrod installs easily on the operating arm pin. (Scheme 3)
Detach the pushrod from the control arm pin. Turn the end piece clockwise approximately 2 turns so that a tension of.078 in (2 mm) is achieved. Hook on the pushrod to the operating arm pin. Install the locking ring. (Scheme 3)
Detach the hose from the diaphragm box. (Scheme 3)
Connect Pressure/Vacuum Pump (30 14 883) to the diaphragm unit and Charge Pressure Gauge (83 93 514). (Scheme 4)
Carefully pump up pressure until the control rod moves to regulate the boost pressure. (Scheme 4)
Just as the control rod starts to move, read off the pressure on the pressure gauge. It should be 6.2-7.0 psi (0.42-0.48 bar). (Scheme 4)
If the pressure is too low, shorten the rod until 6.6 psi (0.45 bar) is obtained.
Undo the pushrod and apply Molycote 1000 (30 20 971), or equivalent to the pin on the operating arm. (Scheme 5)
Install the pushrod and clip, grip the pushrod with a pair of adjustable pliers and lock the nut. (Scheme 5)
Remove the pressure gauge and pump. (Scheme 5)
Reconnect the hose to the diaphragm box. (Scheme 5)
Install the heat shield. (Scheme 6)
Lubricate the "O" ring with vaseline and install the bypass pipe. (Scheme 6) Tighten fasteners to specification, see «TORQUE SPECIFICATIONS»(ref-132873-S26554001722003080500000).

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Adjusting Basic Charging Pressure

Note. Basic charging pressure is the starting point for the TRIONIC system's pressure control function and must therefore be adjusted to the correct level. Compensation of the maximum boost pressure in relation to the current basic charging pressure is carried out continuously through the system's adaptive function. Raising the basic charging pressure above the specified value does not result in a higher boost pressure as the adaptive function will then reduce maximum boost pressure to the normal value (negative adaptation). When adjusting the pushrod stroke, it is important that the pliers used as support are positioned as close to the threads as possible. Turn the end piece so that no burrs are created on the pushrod.

Raise the car and undo the end piece locknut. (Scheme 7)
Break the seal, remove the circlip and unhook the pushrod from the boost pressure control valve's operating arm. (Scheme 7)
Adjusting the basic charging pressure by screwing in the end piece if the pressure is too low or unscrewing the end piece if it is too high. Rotating the end piece 1 turn changes the basic charging pressure by about.3 psi (0.02 bar). (Scheme 8)
Connect the pushrod tot he operating arm and install the circlip. (Scheme 9)
Recheck the basic charging pressure on-road, refer to «CHECKING BASIC CHARGING PRESSURE - ON-ROAD (B205L/R & B235R)»(ref-132873-S34955643472003080400000). If it is not possible to adjust the charging pressure, refer to «CHARGE AIR CONTROL VALVE»(ref-132873-S24791948692003080400000) and «DIAPHRAGM BOX»(ref-132873-S37947522262003080400000) for directions.
Affix a seal to the pushrod.

Scheme 7

Scheme 8

Scheme 9

Charge Air Control Valve

If the basic boost pressure cannot be adjusted, check as follows

Unhook the exhaust pipe bend from the turbocharger and visually check the flap valve's contact with the turbine housing. (Scheme 10)
Break the seal, remove the circlip and unhook the pushrod from the valve's operating arm. (Scheme 10)
Check that the arm moves easily. Change the control valve if it is defective. (Scheme 10)
Reinstall the circlip and affix a seal to the pushrod.

Scheme 10

Diaphragm

If the basic boost pressure cannot be adjusted, check as follows

Check that the pushrod moves freely and does not bind. (Scheme 11)
Check the diaphragm and spring by pumping up the pressure via the diaphragm's nipple. (Scheme 12) Check that the pushrod is pressed out and that it displays no tendency to bind. Release the pressure and check that the pushrod is pulled back into the box. Change the diaphragm if it is defective.

Scheme 11

Scheme 12

Adaptation Of Maximum Boost Pressure

Adaptation of maximum boost pressure takes place continuously during normal driving. If the TRIONIC control module has been removed or if some other measure has been carried out which affects the adaptation level, adaptation can be accelerated and maximum performance achieved sooner by carrying out adaptation of the system as described in the following.

Note. The engine should be thoroughly warmed up with the basic charging pressure correctly adjusted. Use good quality fuel with a high octane rating. If the pressure switch has opened repeatedly because of excessively high boost pressure, maximum negative adaptation will be obtained. This means that maximum boost pressure does not reach its normal value. To restore maximum boost pressure to its normal value, disconnect and reconnect the control module and carry out adaptation as described in the following

Perform wide open throttle acceleration from about 2000-4500 RPM in as high a gear as possible. Since boost pressure must be given time to stabilize in the adaptation range (2750-4000 RPM), it is advisable to carry out adaptation on an uphill gradient. It may be necessary to repeat the procedure until maximum nominal boost pressure, having regard to the grade of fuel, etc., is obtained.

Basic Boost Pressure Control Valve Setting

The wastegate's diaphragm unit is adjusted at the factory and should therefore only be adjusted in connection with repair or change of components. After any adjustment the basic charging pressure should always be checked, see ADJUSTING BASIC CHARGING PRESSURE .

CAUTION

When adjusting the pushrod stroke, it is important that the pliers used as support are positioned as close to the threads as possible. Turn the end piece so that no burrs are created on the pushrod. Adjusting must always be done with the pushrod disconnected from the operating arm.

Loosen the end piece locknut. (Scheme 13)
Break the seal, remove the circlip and disconnect the pushrod from the operating arm. (Scheme 13)
Move the operating arm on the boost pressure control valve towards the "Closed" position and adjust the end piece so that the pushrod can easily be installed on the operating arm's stud. (Scheme 13)
Then screw in the end piece 3.5 turns and tighten the locknut. This gives the boost pressure control valve about 3 mm of preload. (Scheme 14)
Carefully withdraw the pushrod and hook it on the stud of the operating arm. Install the circlip. (Scheme 15)
Check the boost pressure, refer to «CHECKING BASIC CHARGING PRESSURE - ON-ROAD (B205L/R & B235R)»(ref-132873-S34955643472003080400000).
Affix a seal to the pushrod.

Scheme 13

Scheme 14

Scheme 15

Checking & Adjusting Basic Charging Pressure

Remove the bypass pipe with valve, 1 bolt on the turbocharger intake pipe and 1 hose clip on the turbocharger delivery pipe. (Scheme 16)
Remove the exhaust manifold heat shield. The heat shield is attached with a nut and two clips on the underside. (Scheme 16)
Remove the clips from the operating arm with the Circlip tool (83 94 538). (Scheme 16)
Clamp the pushrod with pliers and loosen the locknut with a locknut wrench or the equivalent. (Scheme 17)
Hold the operating arm and undo the pushrod from the operating arm. Secure the control arm, otherwise there is risk of it "jumping over". (Scheme 17)
Move the operating arm on the boost pressure control valve to the "Closed" position and adjust the end piece so that the pushrod can easily be installed on the operating arm pin. (Scheme 17)
Detach the pushrod from the operating arm pin. Turn the end piece clockwise about 2 turns so that tension of.078 in (2 mm) is obtained. Attach the pushrod to the operating arm pin. Install the circlip. (Scheme 17)
Detach the hose marked "W" from the diaphragm. (Scheme 17)
Connect the Pressure/Vacuum pump (30 14 883) to the diaphragm and Boost pressure gauge (83 93 514). (Scheme 18)
Carefully pump up pressure so that the control rod moves to regulate the charge pressure. (Scheme 18)
When the control rod has just started moving, read the pressure on the pressure gauge scale. The pressure should be at least 5.8 psi (0.40 bar) for low pressure turbo and 6.6 psi (0.45 bar) for full turbo. (Scheme 18)
When the pressure is too low the rod is further shortened until 5.8 psi (0.40) bar for low pressure turbo or 6.6 psi (0.45) bar for full turbo is obtained.
Remove the control rod and coat the pin on the operating arm sparingly with Molycote 1000 (30 20 271) or the equivalent. (Scheme 19)
Install the control rod and clip, grip the control rod to prevent it from moving and lock the nut. (Scheme 19)
Disconnect the pressure gauge and pump. (Scheme 19)
Reconnect the hose to the diaphragm. (Scheme 19)
Install the heat shield, coat its stud with Molycote 1000 (30 20 271) or the equivalent and screw on the nut. (Scheme 20)
Lubricate the "O" ring with vaseline and install the bypass pipe. (Scheme 20) Tighten fasteners to specification, see «TORQUE SPECIFICATIONS»(ref-132873-S26554001722003080500000).

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Checking Wastegate Valve (4-Cyl)

CAUTION

Take care if the car is warm. The coolant is hot and there is also a risk of burning yourself on the exhaust manifold.

If it is not possible to adjust the basic charging pressure, check the wastegate valve as follows

Undo the hose clip on the turbocharger pressure pipe and bend the bypass pipe aside. (Scheme 21)
Remove the exhaust manifold heat shield. The heat shield is attached with a nut and two clips on the underside. (Scheme 21)
Undo the nuts securing the front exhaust system to the turbo unit. (Scheme 21) NOTE: The flexible section at the front of the exhaust system should not be bent out of line by more than 7 degrees, i.e. if the front exhaust system is allowed to hang, it must not bend more than the sag caused by its own weight. If the pipe is overloaded, permanent deformation of the components will result. This can cause noise and leakage, and damage at a later stage. NOTE: Apply motor oil or penetrant to the nuts and carefully undo them.
Remove the clip and unhook the pushrod from the control arm on the valve. (Scheme 22)
Observe whether the flap valve abuts firmly against the turbine housing. Check for carbon deposits, etc. (Scheme 22)
Check that the arm moves easily. (Scheme 22)
Hook on the pushrod and Install the lock clip. (Scheme 23)
Attach the front exhaust system to the turbo. Grease the studs with Molycote 1000 (30 20 971). (Scheme 24) Tighten to specs, see «TORQUE SPECIFICATIONS»(ref-132873-S26554001722003080500000). NOTE: When installing the front exhaust system to the turbo, the nuts should be tightened alternately to avoid distorting the flange. The flange must not abut against the turbo connection flange.
Install the heat shield. Press on the left-hand holder first. Apply Molycote 1000 (30 20 971), to the stud. (Scheme 24) Tighten the locknut to specs, see «TORQUE SPECIFICATIONS»(ref-132873-S26554001722003080500000).
Mount the bypass valve with pipe. Install a new "O" ring, greased with vaseline. (Scheme 24) Tighten to specs, see «TORQUE SPECIFICATIONS»(ref-132873-S26554001722003080500000).

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Checking Charge Air Bypass Valve (4-Cyl)

Disconnect the vacuum hose from the charge air bypass valve. (Scheme 25)
Connect the Pressure/Vacuum pump (30 14 883) and build negative pressure in the valve. (Scheme 25)
Check that the diaphragm is intact. If the diaphragm is damaged, no vacuum can be created. (Scheme 25)
Repeat points 2 and 3 but pump up a pressure. (Scheme 26)
Disconnect the pump. (Scheme 26)
Connect the vacuum hose. (Scheme 26)

Scheme 25

Scheme 26

Checking Charge Air Bypass Valve (V6)

Disconnect the vacuum hose from the charge air bypass valve. (Scheme 27)
Connect the Pressure/Vacuum Pump (30 14 883) and build vacuum in the valve. (Scheme 27)
Check that the diaphragm is intact. If the diaphragm is damaged, no vacuum can be created. (Scheme 27)
Repeat steps 2 and 3, but pump up a pressure. (Scheme 28)
Disconnect the pump. (Scheme 28)
Connect the vacuum hose. (Scheme 28)

Scheme 27

Scheme 28

Adjusting Accelerator Pedal Cable (B205L/R & B235R)

Remove the engine cover. (Scheme 29)
Remove the cable adjustment clip. (Scheme 29)
Adjust the cable's play by holding the pedal arm in the fully released position with one hand while pulling the cable taut with the other. Then slacken the cable to the sleeve's nearest notch. (Scheme 29)
Install the clip. (Scheme 29)

Scheme 29

Adjusting Accelerator Pedal Cable (4-Cyl)

Removal

Open the data link connector cover. (Scheme 30)
Undo the screws in the data link connector. (Scheme 30)
Remove the screws and clip securing the lower panel with air duct. (Scheme 30)
Unplug the connector for the floor lighting. (Scheme 31)
Lift out the lower panel.
Disconnect the throttle cable from the throttle pedal by sliding back the bushing and removing it and the cable. (Scheme 31)
Remove the engine cover by releasing the holders one at a time starting at the oil filler. Remove the cover above the throttle valve. (Scheme 32)
Withdraw the cable and its sheathing through the rubber grommet in the bulkhead. (Scheme 32)
Disconnect the throttle cable from the throttle body. (Scheme 33)
Turn the lock clip for the throttle cable adjuster and then pull out the sheathing. (Scheme 33)

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Installation

Grease the rubber grommet in the bulkhead with vaseline and push the cable and its sheathing through the hole in the grommet from the engine bay side. (Scheme 34)
Pull the cable through the bulkhead and into the cabin.
Hook the cable onto the throttle body in the engine bay. Install the clip and secure it. (Scheme 34)
Attach the wire to the accelerator pedal. (Scheme 35)
Loosen the clip for adjusting the cable. Adjust the cable by holding the throttle cam against the stop (closed) with one hand and pulling the cable with the other hand until it is properly tensioned. Then release back to the next groove in the sleeve and install the clip. Replace the cover above the throttle valve and the engine cover. (Scheme 36)
Install the connector to the floor lighting. (Scheme 37)
Install the data link connector retaining screws and tighten them. (Scheme 37)
Install the lower panel. (Scheme 37)
Close the data link connector cover. (Scheme 37)

Scheme 34

Scheme 35

Scheme 36

Scheme 37

Adjusting Accelerator Pedal Cable (V6)