pulsating boost
 

having a problem with sti 2, i´m getting pulsating boost on hard acceleration and it doesn´t reach as high as it should. i hear turbo whistle and the sound is also pulsating. sometimes it is not pulsating but boost isn´t as high it should. no fault codes, changed faulty knock, map and coilpacks, spark plugs are 8 months old. looked the ecu parameters and everything was ok except for alternator voltage which was 12,4v, it should be 13,8 volts. could it be that coilpacks are not getting enough volts? or is the boost solenoid faulty? it is clean. i have no more ideas.

anyone some ideas?

Hello mate i had same sort of issues on my00, Read this thread. Touch wood mine is ok at the minute.

https://www.scoobynet.com/general-te...ing-boost.html

i have cleaned the solenoid and waistgate moves fine. my boost is not pulsating much 0,1 or 0,15 bar. we thought it could be spark issue, so can alternator not charging as much it should caus problems with spark?

double checked charging voltage and it was 13.95 volts. so it is not an issue. it has to be something else.

tried another boost solenoid, but it was hard to tell the difference, maybe it was slightly better. but light pulsating was still there. i don´t know what to try next.

I have the same issue on my blobeye after it's latest remap when accelerating hard in 5th and 6th.

The guy who mapped it at the garage said it's because its maxing out the wastegate duty cycle with the amount of boost I'm running.

He said I could either turn down the boost marginally until it stops happening, or just upgrade to a larger turbo/wastegate combo (which I plan on doing anyway).

He shouldn't have given it back to you with the problem.

its not all about boost, just creates more heat, then knock, get him to pull back the boost till you decide to get your bigger turbo etc.

finally i found the cause, fuel pressure regulator hose was loose. it must have gotten loose after i changed coilpacks. no it runs fine as it should.

Excellent. :)

glad to here you sorted it i have been following this thread as i had the same prob on my96 wagon where abouts it the fuel pressure reg? i am gonna see if mine is loose ive tried everything else

On the driver side bank, by the turbo. If you crane your head over that area and look down into the abyss lol by the cyl. head, you'll see it attached to the end of the fuel rail - looks a bit like a little DV valve with the vac pipe going to it...

Subaru OEM FPR

cheers i will have a look in the morning if i'm not to hungover :)

Link to a pic of it added to my previous post ^^^ :)