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Jerky at full boost

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Old Mar 11, 2006 | 02:45 PM
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Default Jerky at full boost

Hi!

I have a little problem. Everythig works fine untill i press the pedal to the floor at high speed in 4th and 5th gear and the boost hit its limmit. Its kinda jerky and feels like its not producing maximum power. The car is an my93 wrx jdm.

Do anyone have a good idea what the problem could be?
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Old Mar 11, 2006 | 04:40 PM
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Anybody?
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Old Mar 11, 2006 | 05:52 PM
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Possibly fuel cut.
If you have a decat down pipe this will agrivate the condition.
It can tend to happen on cold wet days more than hot summer days.

Only real fix is to remap if possible the ecu.

Graham

ps: sure you are not hitting the rev limiter?!
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Old Mar 11, 2006 | 06:28 PM
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Originally Posted by 911
Possibly fuel cut.
If you have a decat down pipe this will agrivate the condition.
It can tend to happen on cold wet days more than hot summer days.

Only real fix is to remap if possible the ecu.

Graham

ps: sure you are not hitting the rev limiter?!

I dont think its the fuel cut. The car is original apart from dawes and vos chip. And i´m not hitting the rev limiter
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Old Mar 11, 2006 | 07:07 PM
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The MAF? Here is my experience:

Had a simliar problem a while back after driving though some deep flood water - initially no problem but after a few miles the car became jerky and very slow at higher revs in 4th/5th - no problem 1st to 3rd. Then the engine warning light came on...Subaru Assist came out and cleared a reported fault with the MAF. After that no problems since.

We have also suffered similar low power/jerky delivery problems with MAF's on turbocharged VW engines so its one thing worth having a look at.
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Old Mar 11, 2006 | 07:08 PM
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What do you think about replacing sparkplugs and if that doesnt help check the ignition coil. I´ll probably check the MAF also
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Old Mar 11, 2006 | 10:15 PM
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Originally Posted by boan81
Hi!

I have a little problem. Everythig works fine untill i press the pedal to the floor at high speed in 4th and 5th gear and the boost hit its limmit. Its kinda jerky and feels like its not producing maximum power. The car is an my93 wrx jdm.

Do anyone have a good idea what the problem could be?
Sounds like overboost which then brings in a very severe fuel cut like hitting a brick wall. If so, check your boost solenoid.
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Old Mar 12, 2006 | 12:32 AM
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Im only boosting 0,6 bar so i don´t think thats the problem. It doesnt fell like im slightly hitting the brakes, it´s more like the engine is hesitating if you get what i mean.
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Old Mar 12, 2006 | 08:45 AM
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i had exactly the same as this and it was the plugs mate
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Old Mar 12, 2006 | 10:09 AM
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check plugs and coil packs. If your plugs are due a change then change them, whilst doing that check the coil packs for cracks and bits missing (they have a rubber cap, remove this carefully to check the condition.)
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Old Mar 12, 2006 | 03:14 PM
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I´ll check ta sparkplugs and the coils. I´ll the ecu for codes and reset it tonight. Is there an easy way that i can find out if the fuelpump is bad?

Is it possible that the vos chip have caused the problem?
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