Erratic Boost After Rica

[irf]

right, i'm having a little problem and was hoping for your input as a lot more of you seem to run upgraded maps with EBCs.

i used to run a greddy profec B at 14-15psi. recently got an AUTO RICA 304 map for may manual 850. put it in, didn't work. the three hoses with the BCS was the reason as i had blocked the blue one going into the intake. once that was plumbed back in i

start getting 18psi.

trouble is though i sometimes get 18psi and sometimes 12.

from what i've seen, if i were to start at say 40mph in 2nd gear or in other words, high revs, i only get the 12psi all the way through the gears up into 4th.

if i were to start in third gear at say 20mph, i'd get the full fat 18psi.

also noticed some pulsing now where it goes back and forth from 18-15-18 etc

i was thinking to connect my EBC back on and if i were to get a solid 17-18psi this would just show that my BCS is gone as this would be the only difference?

am i on the right track? any help appreciated guys, thanks.

ps. have actually changed the bcs for one that was actually holding 1.3bar which is confusing me lol.

[Volvoson]

Yes, you are on the right track. Try a different BCS or your EBC to rule that your current BCS is causing the large change in boost pressure.

[prasamin]

plugging your intake part of the bcs shouldn't make a difference.

Like 95R said, I would check the BCS first, but I think something is up with the EBC, or you have a leak or crack somewhere.

[irf]

plugging your intake part of the bcs shouldn't make a difference.

Like 95R said, I would check the BCS first, but I think something is up with the EBC, or you have a leak or crack somewhere.

definetly did though. it was the only change i made and the car went from no RICA to lots f RICA

could have a leak but i have changed the pcv and all vacuum lines and some other stuff as wll so i'd hope not. vacuum is at 21 at idle.

thanks for the help guys, definetly gonna plug the EBC in and see what happens.

[irf]

man, i definetly need some help here. thought i'd go for a drive and see whats happening. same thing, sometimes getting up to 18psi but then pulsing back and forwards to 15psi or just giving 12 and sometimes 15psi

so i connected my greddy up. first at minimum i was getting 1opsi, turned it up halfway and got 14-15psi , then just to see what happened, turned it to maximum and still 14-15psi

someone tell me please, wtf is going on with my car

in my amateur thoughts i'm thinking boost leak? even though i've done shitloads to sort that, maybe something else needs doing.

help. please :)

[maiku]

is it not boost fade?

turbo can't take the boost?

[volvo4lif3]

is it not boost fade?

turbo can't take the boost?

Even it were a 16T it could handle 18psi, and its not boost fade if its going from 18-12. From 18-15 I would say fade, sure. However, it has to be a leak or something of that nature.

Have you done a complete stage 0? Go over all hoses, and look for tears etc. Eliminate everything you might think is causing your problem.

[Volvo_Vinny]

is it safe to run 18 psi on a 16t

[Yellow95]

My 16T faded to 12 lbs under heavy load in second. Hits 15+ everywhere else. I think its fade also.

Gary

[maiku]

my 16T had boost fade with my chip

went from 18psi back down to 15

with my 18T, stays at 18-19psi solid

[irf]

15G guys

thing is though when it does hit 18psi it kind of pulses between 18 down to 15, up and down like its trying to hit 18psi but something starts trying to restrict it. thats how it feels and confirmed seeing the boost gauge going up and down.

now i've been thinking about it, it's making sense in my mind to be a boost leak but even that, i've done the pcv, changed all the vacuum pipes i can see, inspected the throttle body pipe, sealed the forge cbv in properly, tightened the wastegate 2 turns. i'm stumped tbh

4.20 am here. i need some sleep.

[maiku]

i still think it's boost fade

your turbo can't hold the boost levels

[socal850tuner]

This is my idea... if any of the hoses expand causing a leak that would release pressure obviously. But when it returns to normal (after leaking for a moment) it closes back up creating a seal. That would explain I think. Key words I think.

[Denovae]

boost fade can be tricky. do a boost leak test.

18psi down to 12psi can be boost fade + a boost leak. also it depends on if you're hitting 18psi and it's seeing knock and pulling timing which could decrease boost slightly ontop of a leak.

boost leak test. fix. zip-tie. boost leak test. then try other things. I've seen so many problems arise from boost leaks it's not funny. I had one boost leak that created a horrible idle... another that took out my vac assisted brakes... it's PITA to diagnose problems w/o testing your car for leaks.

[EricF]

It's a common thing for Motronic to do... It lowers boost if knock is detected, then raises it back to standard level once the knock events have stopped. If it starts again, it will lower again...

If you don't think your car is knocking, put the EBC back on and forget about it.

Motronic does weird things, I don't really like its boost control.