cut off under acceleration
11-02-2011, 12:17 PM
#1
cut off under acceleration
I have noticed that my 97 TT have cut off ignition/injection under acceleration on the road...
Whem the boost aproaches to 0.8 Bar it cut compleatelly coud this be an overboost?
I suspect the wastegates are locked on axle...
Any ideas?
Regards
Luiz Leão
Curitiba Brazil
Whem the boost aproaches to 0.8 Bar it cut compleatelly coud this be an overboost?
I suspect the wastegates are locked on axle...
Any ideas?
Regards
Luiz Leão
Curitiba Brazil
Last edited by luizinholeao; 11-02-2011 at 09:54 PM.
11-02-2011, 08:58 PM
#5
Thanks in advance friends!
Does it cut off or kind of spudder?
Cut off totally, and restart as the boost drops near zero, so i suspect the trouble is something about turbo system.
The only thing I can think of is a faulty/failing DME relay.
I dont suspect it, because i have changed it last week!!, and when it burns there is no fuel pump operation at all.
Hi Luiz - Is the check engine light illuminated? Can you scan for any stored codes? Are your turbo hoses attached securely?
No check lights illuminated, i will try scan the codes tomorrow, and check the turbo hoses!
I bought this car some months ago, and it became from a private collection, so at last ten years, just the engine runs inside a museum, and it wasnt recorded any miles at all!!!
Actually the odo reads just 294 kms!!!
I suspect the wastegates are locked due to corrosion on axle due to un-operation at last 13 years, causing overboost, could this be true?
Many Thanks ,
Regards from Brazil!
Does it cut off or kind of spudder?
Cut off totally, and restart as the boost drops near zero, so i suspect the trouble is something about turbo system.
The only thing I can think of is a faulty/failing DME relay.
I dont suspect it, because i have changed it last week!!, and when it burns there is no fuel pump operation at all.
Hi Luiz - Is the check engine light illuminated? Can you scan for any stored codes? Are your turbo hoses attached securely?
No check lights illuminated, i will try scan the codes tomorrow, and check the turbo hoses!
I bought this car some months ago, and it became from a private collection, so at last ten years, just the engine runs inside a museum, and it wasnt recorded any miles at all!!!
Actually the odo reads just 294 kms!!!
I suspect the wastegates are locked due to corrosion on axle due to un-operation at last 13 years, causing overboost, could this be true?
Many Thanks ,
Regards from Brazil!
Last edited by luizinholeao; 11-02-2011 at 09:52 PM.
11-03-2011, 12:45 PM
#7
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if the car has 183 miles, you should still be breaking the engine in, so follow that procedure. Its sounds like you are pushing the car quite hard for its mileage.
Regardless, the behavior you are seeing is not normal. The 0.8 bar is normal under full load, so does it keep to 0.8 for a while, or just as the turbos are spooling up to 0.8? Do you hit the rev limiter, or it does not matter what the engine RPM is, its the pressure from the turbos?
Cheers,
Mike
Regardless, the behavior you are seeing is not normal. The 0.8 bar is normal under full load, so does it keep to 0.8 for a while, or just as the turbos are spooling up to 0.8? Do you hit the rev limiter, or it does not matter what the engine RPM is, its the pressure from the turbos?
Cheers,
Mike
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11-03-2011, 02:46 PM
#8
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If you suspect the wastegate, lift the back end, undo the rear engine tray by undoing four screws using philips screwdriver and the turbos will be very accessible from there. Just give the wastegates a pull to check if they are stuck. A proper diagnosis would be to use a boost pump and follow the service procedure to check and make sure you don't have a rubber hose cracked somewhere or maybe a mouse chewed threw it. It is possible for the display to show .8 bar and actually be overboosting, i believe the gauge shows at maximum 0.8 bar and won't display any value greater than 0.8 bar even if the actual boost is higher. Another method may be to hook up a standard gauge to the intake manifold or i/c (I think the i/c may have a test port) and verify the boost pressure value.
11-03-2011, 09:26 PM
#10
Dear friends,
Mike: it cuts off just when the boost raise to 0,8... cruising softly at 60mph and get a pedal to floor. no matter how many RPM´s!
I´ve not hitted the rev limit by now...
No abuses at the time!
Uicnick: i will try all of this next week, very good ideas! thanx a lot!
UserA: please tell me more about a diverter valve, i´m a rookie about a turbo 993!
Thanx for the moment friends!
Regards,
Luiz
Mike: it cuts off just when the boost raise to 0,8... cruising softly at 60mph and get a pedal to floor. no matter how many RPM´s!
I´ve not hitted the rev limit by now...
No abuses at the time!
Uicnick: i will try all of this next week, very good ideas! thanx a lot!
UserA: please tell me more about a diverter valve, i´m a rookie about a turbo 993!
Thanx for the moment friends!
Regards,
Luiz
11-05-2011, 02:54 AM
#11
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Sounds like an overboost condition with the ECU operating normally, just trying to save itself.
Could be sticky wastegates and or diverter valves.
Change the spark plugs!!
Could be sticky wastegates and or diverter valves.
Change the spark plugs!!
11-06-2011, 06:13 PM
#12
Why do I feel so left out!
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^^^^^ What he said +993
11-07-2011, 12:02 PM
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Lowest mileage 993 Turbo, in existance!
You should "zero out" all the maintenance, and change every belt, hose, fluid, filter, plug, and etc. Drive about 1,000 miles, and change the oil again.
You should "zero out" all the maintenance, and change every belt, hose, fluid, filter, plug, and etc. Drive about 1,000 miles, and change the oil again.
