new owner, problems boosting
 

Hi guys i'm new on here just hoping for some advice,

I've just swapped my old bmw for a '93 wrx wagon and never having one of these before (plenty of cossies and 200sx's) i've got a small issue when on boost,

the car is pretty standard bar a full exhaust, air filter and baily dumpvalve and a boost controller-boost guage in one
i think the problem may be with the boost controller as it wont hold a constant boost pressure its noticeable mostly on motorways,if i touch the throttle and it boosts over 0.5 bar it flutters constantly making the car surge
typically between 0.8 and 0.6 bar, and on acceleration in lower gears you can feel the car holding back, it also occasionally spikes at about 1.1 bar even though its not set to go that far (not knowing if the car would stand that boost pressure i've kept it low ish)

i've checked all the pipes and changed the plugs as a precaution and can only think the controller is at fault.

any info would be greatly appreciated

Lee

what type of boost controller is it ?(make,model)??

its a power enterprise boost controller with guage, done a google search and its over $450 new

i have found some setup instructions and it says it can cause hunting and overboosting if its clashing with the cars factory boost control system if still connected, it recommends removing the factory setup is this wise and if so how could it be done??

i run a blitz electronic boost controller on my wrx and you can switch through different boost settings or switch it off and it runs the standard factory boost again.i'd be tempted to remove your controller and put it back to factory spec,and see if this cures your problem

yeah thinking of doing that tomorrow just to see how it goes, i've noticed tonight it seems to boost better if the engines not up to running temps too

well i've had a play today if i turn off the controller the car boosts fine and holds 0.6 bar without fault, if i turn the controler on and keep it to the same its fine, as soon as i go more than 0.6- say 0.8 it constantly dropps back and rises again, it just wont stay steady. I cant hear any leaks or anything so its really puzzled me???
i've just kept it turned off for now.

0.6bar? It sounds like the standard controller has been unplugged already as standard boost pressure is around 0.8bar. Can you plug the standard stuff back in (if it's still there)? If there you'll see a few black and red sensors on the drivers side inner wing turret. Plugs these back in and disconnect the boost controller. Sometimes the OE items will have been completely removed.

It's my guess that the boost controller has been incorrectly fitted or it is fubared. You could try cleaning it's pipes and sensors through with some carb cleaner..

ok the standard boost system is still intact and plugged in, i've found the actuator to be quite weak (i can pull the bar out with one hand easily), i've adjusted it in a couple of turns to pre load it a bit more and with the boost controller turned off it still holds back and surges between 0.5 and 0.7 bar, seriously noticeable in higher gears when accellerating as the car wont accelerate smoothly at all.
I've heard all sorts of conflicting advice saying coil packs, spark plugs or the dump valve causing the problem.
i'm completely baffled :S

Spark plugs and coil packs would make the car feel sluggish if they were gone, turbo pressure shouldn't be affected though I think. What DV is fitted, is it a standard item? If not fit the OE item, you can get them for a couple a quid. I'd also completely disconnect the controller for now and reconnect all the hoses to the OE solenoids and go from there.

its got a baily dump valve on it which i will remove, as for the original pipes for the boost control i have no idea how they would go to be back to standard

thanks i'll have a play when i get 5 minutes tomorrow

Might sound daft, mine did exactly the same it would boost to 1.2 bar then drop to 0.8 bar then rise again in an almost rocking motion during acceleration.

I had fitted a few mods before this happened though. My garage concluded that the wastegate duty cycle needed altering slightly and it has been fine ever since.

Andy