I have a 1996 mcrae impreza its just done 64000 miles and had its timing belt done about 300 miles ago. Ive had a slight problem which seems to be getting worse and worse and its tricky to explain. When your driving and you put your foot down it seems to accelerate pretty quick but then starts to jerk back and forth when the turbo is just about to kick in at 4000 revs ish. If you keep your foot down eventually it gets passed the jerking but then will do it in the next gear and so on. Sometimes when going up a hill with your foot planted it gets to 4000 and will not go any further at all. When in first gear and you plant it it is fine which makes me think it isnt a turbo problem? Not too sure?

Any help would be greatly appreciated.

Cheers Adam

Sounds like either a misfire or boost cut ,have you done a classic self ecu code check?

I havnt done a ecu check. Do you think plugging a diagnostic machine in could tell me more? Even though there are no lights on the dashboard?

clutch?

I havnt done a ecu check. Do you think plugging a diagnostic machine in could tell me more? Even though there are no lights on the dashboard?

Unless you have an ssm1 dealer tool you won't get much sense out of the ecu,

Have you any idea of mods done ?

You don't have to plug in a machine search "classic ecu code check" I think it's in a sticky thread in the tech section on here ,it allows you to check the codes yourself without any diagnostic equipment and resets the ecu as well .

As stants said does it have any mods ?

When was the last time the plugs were changed?

Do you have a boost gauge if so what does it peak at?

Boost wise it has a boost gauge on and it seems to go to inbetween 0.5 to 1. This is first scooby so dont know much about the turbo guage. The plugs got done about 5 years ago but il probs get some new ones. Mods its pretty standard its a jdm import from japan but hasnt been touched with much still has cat and all original underneath. My dad is a mechanic and has a top spec snapon diagnostic machine but he is a little stumped aswell. Il start with the plugs and see where that goes. Cheers

Does seem like it's over boosting a bit as standard boost is about 0.8 bar across the impreza range .

Pre 97 cars have a 1.2 bar map sensor limit and if the boost pressure is to far out of the ecu's map parameters it can also cause boost cut (sudden loss of all boost)

As for checking codes There's 2 plugs under the dashboard you connect together which give a sort of "morse code" flash of the eml light to read codes

Cheers pal. Thats a big help il look into it. I have held a wire between two fuses before and it flashes my 'antilock brake' light in a moorse code and after a bit of decryption it came up with a faulty g sensor. Dont suppose that might have something to do with it?