Overboost???
04 February 2003, 04:36 PM
#1
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Do you have a boost gauge? normally this kind of thing is fuel cut caused by overboost and happens about 15-16psi. I get it on mine but only in 4th 5th sometimes 3rd if its cold outside.
It has been suggested that I have the wastegate ported as in standard form with the Decat D/P and exhaust it does not allow enough air through the wastegate and the turbo boost pressure starts to run away with itself. (I may have been lied to here but I've spoken to Turbo Dynamics and they say it's quite a common problem on older Impreza's so I hope not).
I plan to have this done fairly soon and hopefully will sort it.
However that might have nothing at all to do with what's happening to your car.
Ade
It has been suggested that I have the wastegate ported as in standard form with the Decat D/P and exhaust it does not allow enough air through the wastegate and the turbo boost pressure starts to run away with itself. (I may have been lied to here but I've spoken to Turbo Dynamics and they say it's quite a common problem on older Impreza's so I hope not).
I plan to have this done fairly soon and hopefully will sort it.
However that might have nothing at all to do with what's happening to your car.
Ade
05 February 2003, 10:55 AM
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This might be worth a try, I had a similar prob with my scooby with a PPP ECU, after cleaning that , adjusting this, I reset the ECU and the problem dissapeared !!!
So far anyway.
So far anyway.
05 February 2003, 01:50 PM
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Do you mean if you rag it through the gears i.e. full throttle in 2nd, hit red-line, chnage into 3rd, press accelerater and it seems like you get a wee delay then blam you're away again.
So just after changing gear there is a 1/2 second delay before you shoot away again?
Doofus?
So just after changing gear there is a 1/2 second delay before you shoot away again?
Doofus?
05 February 2003, 03:24 PM
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I'm going to send mine to turbo dynamics to get the wastegate ported but am waiting for a weekend when I'm not busy and it's not snowing!
I tried pretty much everything else on mine and this is the last option but TD have assured me this will solve the problem. Going to have the inlet done aswell and a general service (rebalanced and any seals that need doing) Should only cost a couple of hundred pounds.
Only problem is trying to resist getting the front entry mod done while the turbo's off!!!
Ade
I tried pretty much everything else on mine and this is the last option but TD have assured me this will solve the problem. Going to have the inlet done aswell and a general service (rebalanced and any seals that need doing) Should only cost a couple of hundred pounds.
Only problem is trying to resist getting the front entry mod done while the turbo's off!!!
Ade
05 February 2003, 03:40 PM
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I was just trying to ascertain what the exact symptoms were ..
Try putting you car in 4th at about 40 and leaving it there, accelerate hard .. it you get the delay it's sounds like overboost. It's not a symptom of changing gear .. you're overboosting and you've hit the fuel cut. Does the cut out occur without changing gears ??
If the delay occurs consistently just after changing gears when ragging it ... it could just be turbo lag. I get this on my MY00 with small turbo so an MY95 will be worse. Changed gear - turbo stops spinning and needs some time before it is back up to speed .. ?
Didn't want to have people looking at porting this/cleaning that until we had a better description.
First of all I'd get a boost gauge installed, then you can at least see what's going on. Overboost should be obvious (not sure what fuel cut is on MY95?) by the amount of PSI you're boosting to.
If this is the case, I'd get a Dawes Device, at least you've got a boost gauge to help set it up correctly.
If it's just Turbo lag ... errrm dunno, VTA BOV?
Doofus.
Try putting you car in 4th at about 40 and leaving it there, accelerate hard .. it you get the delay it's sounds like overboost. It's not a symptom of changing gear .. you're overboosting and you've hit the fuel cut. Does the cut out occur without changing gears ??
If the delay occurs consistently just after changing gears when ragging it ... it could just be turbo lag. I get this on my MY00 with small turbo so an MY95 will be worse. Changed gear - turbo stops spinning and needs some time before it is back up to speed .. ?
Didn't want to have people looking at porting this/cleaning that until we had a better description.
First of all I'd get a boost gauge installed, then you can at least see what's going on. Overboost should be obvious (not sure what fuel cut is on MY95?) by the amount of PSI you're boosting to.
If this is the case, I'd get a Dawes Device, at least you've got a boost gauge to help set it up correctly.
If it's just Turbo lag ... errrm dunno, VTA BOV?
Doofus.
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05 February 2003, 04:38 PM
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Doofus
You're spot on right mate
It's not only on changing gear, I can accelerate in 2nd and it will do it before hitting 3rd and so on and so on
I was racing my mates MY98 (on a private road
) and as I accelerated in 2nd it felt like the car was jumping, chugging etc then all of a sudden it came to life again
I already have a VTA dump valve
Cheers
Paul
You're spot on right mate
It's not only on changing gear, I can accelerate in 2nd and it will do it before hitting 3rd and so on and so on
I was racing my mates MY98 (on a private road
) and as I accelerated in 2nd it felt like the car was jumping, chugging etc then all of a sudden it came to life againI already have a VTA dump valve
Cheers
Paul
05 February 2003, 07:20 PM
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Hanley,
The SIDC website helped me when my car was doing the same. In the FAQ section they explain a couple of possible causes e.g. faulty dump valve or blocked/faulty waste gate.
My car did the same - in 3rd gear, 3000rpm, the engine cuts and it feels like you've hit a brick wall.
The fault on mine was due to oil in the waste gate. This came straight after the 60,000 service performed by a Subaru dealer. They over filled the oil level - gimps.
The SIDC website helped me when my car was doing the same. In the FAQ section they explain a couple of possible causes e.g. faulty dump valve or blocked/faulty waste gate.
My car did the same - in 3rd gear, 3000rpm, the engine cuts and it feels like you've hit a brick wall.
The fault on mine was due to oil in the waste gate. This came straight after the 60,000 service performed by a Subaru dealer. They over filled the oil level - gimps.
02 April 2003, 02:59 PM
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I am running a UK MY95 turbo and when accelerating the car seems to cut out for a second and then carry on, this happens in every gear not long after the gear change.
Is this overboost? Is the ECU killing the engine for a small time?
My car is a MY95 UK turbo with a K&N Induction Kit, Evo Dump Valve and full Magnex de-cat - including downpipe.
Would like some advice on what may be causing this and what I can do to resolve it
Cheers
Paul
Edited to say it really would pi** you off if someone is racing you (not that I'd do that)
[Edited by Hanley - 2/4/2003 4:00:25 PM]
Is this overboost? Is the ECU killing the engine for a small time?
My car is a MY95 UK turbo with a K&N Induction Kit, Evo Dump Valve and full Magnex de-cat - including downpipe.
Would like some advice on what may be causing this and what I can do to resolve it
Cheers
Paul
Edited to say it really would pi** you off if someone is racing you
(not that I'd do that)[Edited by Hanley - 2/4/2003 4:00:25 PM]
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