| Teema ülevaade |
Maku
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postitati 25.12.07 22:52 |
Max side play on an oil journal turbo (K26) is .55mm. end float is
.2mm i would imagine its the same for a K24.
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Maku
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postitati 18.08.06 07:53 |
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Maku
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postitati 01.05.06 11:52 |
Kaits - http://www.sjmautotechnik.com/trouble_shooting/20vboost.html
SJM copy/paste
Introduction
It should be your responsibility (or your mechanics) to check out and verify all the ECU and Fuel Injection system components mounted on your engine
are working correctly BEFORE you do any type of modification that will raise the boost on your vehicle.
Raising the boost on a high mileage car isn't a great idea UNTIL you get the stock system working correctly as it was originally designed when it
left the factory. If you install a stiffer Waste Gate spring or use a valve connected to boost pressure to add pressure on top of the Waste Gate
Diaphragm, you may be unaware if the engine ECU/Fuel system components are not working correctly, because the boost may be raised regardless of the
condition of the stock system components.
Whenever I purchase a used Turbocharged Audi, I check the compression or do a leak down pressure test to verify the engine valves, rings, and head
gasket are in good shape. This leak down test is better than a basic compression test and involves pressurizing the cylinder with air and measuring
the amount of leakage out of the cylinder.
This can pin point cylinder leakage out of the intake or exhaust valves, past the rings, or through the head gasket. I replace the plugs, air filter,
and fuel filter and change the engine oil. I check/replace the O2 sensor. I replace the valve cover gasket and any suspect breather or vacuum hoses.
I make sure the timing belt has been replaced at the suggested 60-90K interval. I remove the lower Intercooler/turbo hose(s) and inspect them, I
check/replace the accordion style hose at the Intercooler connection. It is also very important to check/replace the turbo bypass valve.
On the 1991 200TQ, it is important to Check/Replace the small Bypass valve hose (vacuum/boost hose) that connects from the bypass valve to the small
fitting at the back of the intake manifold. On the 1992-95 S4/S6, you may want to remove the black plastic firewall cover, and replace the crimped on
hose clamps at the ECU vacuum/pressure hose where it connects to the clear moisture trap (Looks like a empty fuel filter) as these hose can blow off
as the boost goes up.
You can also pressure test the intake/boost hoses, by making an adapter that is inserted into the hose between the MAF and the turbo, and then apply
regulated compressed air (~15psi) and pressure test the hoses from the turbo inlet, out the turbo exit hose, through the Intercooler, and into the
throttle. If you are running the 1+ type ECU mods, which produce over 20psi of boost, using the Samco boost hoses may save your screamin K24 turbo
some day.
I check the operation of the idle/potentiometer throttle switch, and I remove and clean the idle stabilizer valve. I check the ECU measurement block
values (10 values) to ensure the ECU is operating the engine as expected. If a problem with the mixture adjustment shows up, the intake vacuum hoses,
or the fuel pressure may need to be checked.
The cooling system integrity should be accessed. Replacing the thermostat, and all the coolant hoses, the heater control valve, the heater core to
engine hoses, the radiator fan temperature sensor, the after-run temp sensor, and the Multi-Function temperature sensor is also a good idea on
vehicles with over 100k miles.
You don't want a $10 hose ruining your expensive 20V engine when the hose blows and causes overheating and a possible blown headgasket! Once I
complete the replacement of these many high mileage components, and ensure the engine/ECU is operating correctly, I can rest assured, and I don't
need to "guess" if they are ok if the car starts running poorly.
Don't get lazy and "assume" these components are ok, just bite the bullet and inspect or replace them as necessary. NOTE: Increasing the boost on
your vehicle may change the emissions output which may not be legal in your area.
Stock Boost Levels-How does the ECU control Boost?
The 1991 200TQ with 20V Turbo Engine was designed to run a maximum of 1.825 bar boost (absolute) or ~12 psi gauge pressure, as set by the Motronic
Engine Control Unit (ECU).
The 1992-96 Audi S4 in overboost mode will have boost set to about 2.15 bar absolute. The actual boost produced will vary depending on engine RPM, air
temperature, fuel quality, and altitude. The 20V boost control system is different than what was used on the earlier 10V Audi Turbo engines.
The ECU uses the Waste Gate solenoid to send boost to the lower chamber in the waste gate to open up the waste gate at the appropriate boost level.
The Waste Gate solenoid valve is designed to be open with no electrical signal applied, which will send turbo boost pressure directly to the lower
chamber in the waste gate and open the waste gate at a pressure only determined by the stiffness of the waste gate spring.
When the waste gate solenoid is energized with a high duty cycle, (more on time) the waste gate solenoid will prevent boost pressure from reaching the
waste gate lower chamber, and allow the boost pressure to climb higher. The boost will climb, until the required boost level set in the ECU is
reached, at which point, the duty cycle percentage (%) to the waste gate solenoid will be reduced, so the boost pressure will once again be sent to
the lower chamber in the waste gate diaphragm and the boost pressure will be controlled. In the stock 20V engines, this corresponds to about 1.4-1.5
bar of boost as controlled by the waste gate spring. If you completely remove the lower waste gate hose, or block it off, the waste gate will only
open when "exhaust" pressure acting on the waste gate valve face, exceeds the waste gate spring pressure.
This is why a modified 20V ECU can make 2.25 bar absolute boost pressure, even with the stock waste gate spring installed. The ECU uses a barometric
sensor to monitor the altitude the vehicle is at, and will trim back the boost slightly as the altitude increases above 3900 feet. For example, in the
1991 200TQ 20V, the boost will be reduced to about 1.715 bar absolute, when the altitude is above 8500 feet [1].
Boost Problem Checklist
Here is a checklist you can go through when you have low or high boost problems.
LOW BOOST or Running poor issues
• Check for any stored ECU fault codes, are the knock sensors working ok?
• Read the Measurement block values using the VAG-COM, look for anything out of the range
• Check basic engine timing, flywheel, camshaft and distributor rotor position
• Check Throttle Cable Adjustment
• Check Air Filter, is it really clogged up?
• Check/Replace the Turbo Bypass Valve, check small vacuum/boost hose to this valve
• Check Idle Stabilizer Hoses, and other small vacuum/boost hoses
• Check basic fuel pressure and correct operation of the rising rate fuel pressure action by applying vacuum or boost to the vacuum/boost hose
connection
• Check fuel pressure regulator for leaking into the vacuum/boost hose fitting (rich running)
• Check ECU moisture trap hoses (fuel filter lookin thang) behind black firewall cover (AAN S4/S6)
• Check ECU Connector Terminals for corrosion, remove connector and use contact cleaner
• Replace small vacuum hose from Bypass valve to Intake Manifold (3B engine)
• Check the Operation of the Multi-Function Temp Sensor (1991 200Tq 20V Only)
• Temporarily disconnect Multi-Function Temp Sensor 4 pin connector and recheck boost output (1991 200Tq 20V Only)
• Remove and inspect the Intercooler exit hose (Ribbed Hose) and the lower turbo exit pressure hose for leaks.
• Check the rubber hose between the intake pipe and the throttle body.
• Check Vacuum hoses and their connections at the back of the intake manifold
• Check/Replace the coolant thermostat, is the engine running too cold? or too hot?
• Check Engine Coolant Temperature Sensor Resistance and connector wiring
• Check the operation of the Waste Gate Solenoid using the ECU Output Test
• Check Waste Gate Solenoid hoses
• Check Air Temp sensor resistance at the ECU, and Repair the Air Temp Sensor wiring connections if needed.
• Check Throttle Position Switch/Potentiometer for intermittent operation
• Check Altitude Sensor Voltage Output and wiring between sensor and ECU
• Plug or pinch off hose to lower waste gate and check for maximum boost and overboost cutout
• Check Waste Gate for sticking open, defective spring?
• Check the Exhaust System Back pressure, possible exhaust restriction
• Inspect the Turbo inlet vanes and end play, has the turbo compressor nut left the building? or the turbo seized up, broken in half, or otherwise
gone south?
OVERBOOST PROBLEMS (BOOST TOO HIGH)
• Check Lower Waste Gate Hose from Intake Manifold for leaks/restrictions
• Check the operation of the Waste Gate Solenoid using the ECU Output Test
• Check Vacuum/Boost Hose from Intake Manifold to Engine Control Unit (ECU) for leaks
• Pressure test the intake/boost hoses using hose adapter and compressed air regulator adjusted to 15psi.
• Check and clean the electrical connections at the MAF sensor
• Check Waste Gate Diaphragm for Leaks
• Check Waste Gate Valve for sticking or restricted movement
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genekas
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postitati 18.10.05 11:53 |
nujaa - saab sedagi tegelt...
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inc13
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postitati 16.10.05 23:52 |
| Tsitaat: | Algselt postitas: generaator M
no otse loomulikult võib, kui aju sisu veidike muuta |
Ajuväliselt
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genekas
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postitati 16.10.05 23:34 |
no otse loomulikult võib, kui aju sisu veidike muuta
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inc13
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postitati 16.10.05 22:07 |
| Tsitaat: | Algselt postitas: generaator M
Sama on ka ABY/AAN juures - sellepärast ongi stock ajuga sellise mootori puhul suurema ja tõhusama vahejahuti poolt saadav efekt
küsitav - aju keerab sisselaskeõhu jahenedes boosti maha 
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Alati võib sellise lolluse suht lihtsalt "ära keelata"
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genekas
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postitati 10.10.05 22:44 |
| Tsitaat: | Algselt postitas: quattromees
...Kuuma ilmaga rõhk kõrgem, et kompenseerida soojema õhuga tekkivat väiksemat võimsust... |
Sama on ka ABY/AAN juures - sellepärast ongi stock ajuga sellise mootori puhul suurema ja tõhusama vahejahuti poolt saadav efekt
küsitav - aju keerab sisselaskeõhu jahenedes boosti maha
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forsin
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postitati 07.10.05 10:06 |
| Tsitaat: | Algselt postitas: Kotkas
Mäletan,et kui sain auto oma valdusesse, siis sain näiduks samuti 1,8 bar. Stock mootoriga ei viitsinud rõhku kompuutril ees hoida. Aga enne
chippamist mäletan, et rõhk ei läinud üle 1,6-1,7 enam. Mis võis selle põhjustada? |
Tere kui sul tekib soov oma paljuklapiline nuhtlus ???????
teha võimalikult odavalt (vähe lisa juppe osta )
meeldivalt sportlikuks limusiiniks (oletavasti väheneb ka kütuse kulu mootori töö täpsemaks tegemisega )
Siis võta ühendust. -forsin-
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Ulvar
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postitati 04.05.05 08:49 |
| Tsitaat: | Algselt postitas: Kotkas
Mäletan,et kui sain auto oma valdusesse, siis sain näiduks samuti 1,8 bar. Stock mootoriga ei viitsinud rõhku kompuutril ees hoida. Aga enne
chippamist mäletan, et rõhk ei läinud üle 1,6-1,7 enam. Mis võis selle põhjustada? |
Käi kogu turbo ja sisselaske vaheline osa üle ja vaata, et kuskilt ühenduskohtadest õline poleks ehk läbi ei laseks. Väikest leket ei pane muidu
tähelegi, lihtsalt rõhk ei taha enam eriti kähku üles minna.
Lisaks, minuteada näitab see kompuuter ka 1,79 puhul 1,7.
Ulvar
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Kotkas
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postitati 03.05.05 21:00 |
Mäletan,et kui sain auto oma valdusesse, siis sain näiduks samuti 1,8 bar. Stock mootoriga ei viitsinud rõhku kompuutril ees hoida. Aga enne
chippamist mäletan, et rõhk ei läinud üle 1,6-1,7 enam. Mis võis selle põhjustada?
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quattromees
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postitati 03.05.05 20:37 |
Kuni 0.8 bar üle. Seda sõltuvalt välistemperatuurist, õhurõhust jne. Kuuma ilmaga rõhk kõrgem, et kompenseerida soojema õhuga tekkivat väiksemat
võimsust. Eesmärk, et auto liiguks iga ilmaga samamoodi.
Nii kirjutab www.sjmautotechnik.com
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Kaits
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postitati 03.05.05 20:35 |
Turborõhk: 1.8bar, e. 0.8bar ülerõhku.
Allikas: http://members.aol.com/c1j1miller/200-specs.html
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Kotkas
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postitati 03.05.05 19:42 |
Selline lihtne küsimus, et palju peaks turbo rõhku puhuma 3b mootoril tehase sedes? Sama küsiks ka õlirõhu kohta, et millise näiduga võib rahule jääda
tulise (mitte sooja  )mootoriga? Otsing ei aidanud...
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