problems boosting on my 1998 classic....help please

[jay09]

hi all,need help here as its doing my head in,i bought my subaru impreza in april and it was running fine,ie boosting ok.then the problem started.when hitting boost there was a slight mis fire,didnt think much of it but then it got worse,to the point where is wont boost after about 3000 rpm,its not a sudden hit like fuel cut it just makes a burbeling noise and wont boost anymore,since this ive changed the maf,coil pack which made no difference,today i changed the spark plugs,it has made it better but still wont boost,im going to order a new set of ht leads and see what happens,just wonderd if anyone had any ideas because im running out of ideas and getting sick of spending money in places it doesnt need it.

ps i did a ecu fault check and its not reading any codes.ive checked all boost pipes and they seem fine,even the solinoid is clicking good when under testing.would b gratefull for any info.

thanx guys

[ROBBIE-T2000]

id check dump valve then headers/up pipe

[jay09]

id check dump valve then headers/up pipe

ok great thanx ill have a look,ive looked at the dump valve and it seems ok,its a hks blow off valve fairley new aswel.

[Vimmy]

Have you got a boost gauge attached to see what levels of boost you do have, could it been some split/perforated vacuum pipe that leaks only under the highest of pressure perhaps? Do you know what boost levels you have currently?

Cheers,

Col

[jay09]

Have you got a boost gauge attached to see what levels of boost you do have, could it been some split/perforated vacuum pipe that leaks only under the highest of pressure perhaps? Do you know what boost levels you have currently?

Cheers,

Col

hi no havnt got a boost gauge fitted,but put a manual boost controller on and turn boost fully down,still no different.

[Vimmy]

It might be worth getting hold of a gauge to see that the levels are in also to be able to see any spikes or dips as they occur? If the boost controller is still turned down low, it may not show up any possible leaks?

Cheers,

Col

[jay09]

It might be worth getting hold of a gauge to see that the levels are in also to be able to see any spikes or dips as they occur? If the boost controller is still turned down low, it may not show up any possible leaks?

Cheers,

Col

ok great thanx ill get one fitted and have a look.

[MattC]

im interested to know what cures this problem cause the classic im getting has a similar isue but its completly standard.

[Vimmy]

I've not heard anything back, so I'm guessing the problem has gone away?