rapid.STI

iTrader: (5)

Hello lads,

Right i have a friends car which im trying to get right for him. It has an issue with boost.
Basically when he brought it he said his mate had adjusted the waste gate arm and the pipes from the boost soliniod were not plumbed in right

So last time i had the car i backed the waste gate down, plumbed the boost pipes the correct way and gave him it back. It all seemed fine round the city roads.

Anyway when he picked it up and traveled home by motorway he said it was 100% better. Anyway a week or so later he is on the motorway and under hard acceleration in 5th it was getting boost/fuel cut.

Yesterday/today i have the car back with me and this time he brought a boost gauge, so i plumbed in the gauge and took it for a spin. Ive adjusted the wastegate so its boosting just under 1bar. (0.9) i have cleaned the bosst solanoid, adjusted the dumpvalve, backed the wastegate off, fixed a broken pipe on the air resonator box and now it has the same issue just not as bad

It doesnt have any issue in 4th or 5th now but it wont hold boost under hard acceleration in third? It hits 0.9 then flickers between 0.7 & 0.9 to where it then spikes just over 1bar? The car has a judder at the same time, not violent but a judder you can feel.

The car is fine if you feather it in nice at around 4500k rpm. Hit the pedal hard and it doesnt like it?

So the only other thing i can think of is replacing the solinoid itself? But then my friend has spent a small fortune on trying to put it right.

Please does anyone have a idea's?

Sorry its a long one but i wanted to explain as best i could so we dont get any random guesses like change this, change that.

Car itself is a 1993/4 wrx import with 181000 miles.

Its had lamba sensor, engine temp sender, maf, cam sensor, coil packs & plugs, dumpvalve, solinoid cleaned, ristrictor pill checked, pipes checked, air filter changed, throttle body changed, i think he also mentioned the ecu as well.

Thanks for reading.

Wayne.

dj219957

check the restrictor pill is still present in the bottom hose on the solenoid.
car will never hold as much boost in 1st 2nd or 3rd as it will in 4th or 5th. thats normal.

rapid.STI

iTrader: (5)

Thanks matey but ive already checked the pill

mr sti123

Hi there sounds to me as though its hitting the boost limit not sure if it should boost as high as 1bar but standard im sure should be lower. you may want to try different pill so it doesnt bleed too much air away from actuator

4950ken

iTrader: (49)

The bit about it spiking to over 1 bar in 3rd makes me think there is something not working right in the boost control side of things.

If I were you I would swap the entire map pack from one of your cars that is the same year and has the same turbo and give it a try with that. The map pack is the bunch of stuff on the drivers side strut top along with the boost solenoid. Swap the whole lot including the boost pipework (if possible and compatible) and see how the car goes with that on. If the problem is resolved then it shows there is something wrong with one of the pieces in the original pack, so you can then go about replacing them one by one and seeing if it is fixed with that.

If you use the whole pack and there is no difference then obviously it is not related to the boost solenoid, pressure exchange solenoid or map sensor etc. and you will know to look somewhere else for the solution, it will at least eliminate it hopefully without cleaning out your mate's wallet.

Hope this helps.

Ken

Joe will

iTrader: (9)

cracked exhaust housing i had this problem!

hope alls well with linden, take care