Help! Max boost 13psi
Mar 22, 2019, 08:01 AM
#16
Hmm very strange. Have you done a BLT to see if you have an vac leaks? I'd trace the lines back and confirm all is where they are supposed to be. Its just weird that you seem to be running right around wastegate pressure. Even with a large boost leak the car should still have no problem producing target boost, its just going to be blowing hot air and will most likely fall off sooner.
Maybe also take a look at the wastegate and see that the flapper is seating as it should. Wonder if something in there broke and its trying to build boost while cracked open? Sorry I may have mislead you as typically when youre running WG pressure the issue stems from the boost control thus all it has to stop it from blowing open is spring pressure of the gate. Now that I type this out I think I would would to investigate the wastegate further.
Maybe also take a look at the wastegate and see that the flapper is seating as it should. Wonder if something in there broke and its trying to build boost while cracked open? Sorry I may have mislead you as typically when youre running WG pressure the issue stems from the boost control thus all it has to stop it from blowing open is spring pressure of the gate. Now that I type this out I think I would would to investigate the wastegate further.
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V9RS (Mar 22, 2019)
Mar 22, 2019, 08:23 AM
#17
Newbie
Thread Starter
Hmm very strange. Have you done a BLT to see if you have an vac leaks? I'd trace the lines back and confirm all is where they are supposed to be. Its just weird that you seem to be running right around wastegate pressure. Even with a large boost leak the car should still have no problem producing target boost, its just going to be blowing hot air and will most likely fall off sooner.
Maybe also take a look at the wastegate and see that the flapper is seating as it should. Wonder if something in there broke and its trying to build boost while cracked open? Sorry I may have mislead you as typically when youre running WG pressure the issue stems from the boost control thus all it has to stop it from blowing open is spring pressure of the gate. Now that I type this out I think I would would to investigate the wastegate further.
Maybe also take a look at the wastegate and see that the flapper is seating as it should. Wonder if something in there broke and its trying to build boost while cracked open? Sorry I may have mislead you as typically when youre running WG pressure the issue stems from the boost control thus all it has to stop it from blowing open is spring pressure of the gate. Now that I type this out I think I would would to investigate the wastegate further.
It certainly feels very lonely and helpless to own the only ix rs in the country with basically no local specialists that can service the car.
Could the 13psi max boost indicate that the wastegate is stuck open?
I spoke to several specialists in the UK and Thailand, and they confirmed exactly what you mentioned:
One mentions wastegate actuator being a potential culprit, and that replacing the vacuum lines will probably not help much.
So please do comment on my next logical steps:
1. Visually check wastegate actuator arm
2. Replace vacuum lines (BCS to wastegate and turbo 'T' line)
If this does not fix the issue then,
3. Replace wastegate actuator
Mar 22, 2019, 08:38 AM
#18
Newbie
Thread Starter
Also, could it be down to ECU disabling boost control due to knock detection?
The max boost was lost on a very hot hazy day (40c)
I wonder if it is worth removing the battery to reset ecu.
The max boost was lost on a very hot hazy day (40c)
I wonder if it is worth removing the battery to reset ecu.
Mar 22, 2019, 11:39 AM
#19
From what I'm told the factory ecu does have some boost limited control although I believe its fairly limited and most of the knock protection is done from pulling timing. Do you have a cable and evoscan to datalog the car to see if its actually knocking?
As for replacing vacuum lines, unless there is a pinhole leak somewhere or something is physically disconnected I doubt that is the culprit here.
Check the WG arm and report back as far as how it feels. You might need to pull the o2 housing to visually see if the flapper is actually seated as it should be. I wonder if you could disconnect the downpipe and shine a light in there but Im not so sure that'll even work.
As for replacing vacuum lines, unless there is a pinhole leak somewhere or something is physically disconnected I doubt that is the culprit here.
Check the WG arm and report back as far as how it feels. You might need to pull the o2 housing to visually see if the flapper is actually seated as it should be. I wonder if you could disconnect the downpipe and shine a light in there but Im not so sure that'll even work.
Mar 23, 2019, 04:50 AM
#20
Newbie
Thread Starter
From what I'm told the factory ecu does have some boost limited control although I believe its fairly limited and most of the knock protection is done from pulling timing. Do you have a cable and evoscan to datalog the car to see if its actually knocking?
As for replacing vacuum lines, unless there is a pinhole leak somewhere or something is physically disconnected I doubt that is the culprit here.
Check the WG arm and report back as far as how it feels. You might need to pull the o2 housing to visually see if the flapper is actually seated as it should be. I wonder if you could disconnect the downpipe and shine a light in there but Im not so sure that'll even work.
As for replacing vacuum lines, unless there is a pinhole leak somewhere or something is physically disconnected I doubt that is the culprit here.
Check the WG arm and report back as far as how it feels. You might need to pull the o2 housing to visually see if the flapper is actually seated as it should be. I wonder if you could disconnect the downpipe and shine a light in there but Im not so sure that'll even work.
Car drives smoothly as usual and boost still comes on progressively and peaks at 13psi - no spike or random swing.
How do I check the actuator’s arm when it is still attached inside the engine bay?
Also, would it make sense to just replace the wastegate actuator?
Car seems to be in good health as I still get thrown back into seat when boost comes on 🤨
Mar 23, 2019, 06:34 AM
#21
My hunch is that its a flapper issue not so much the actual wastegate. In that last picture you posted remove that clip and slip off the WG arm. Be careful of the radiator maybe throw a piece of cardboard in there to be safe. It will be under tension so it's not just going to slip off so pulling slightly upward to relieve the spring pressure then outward and it will come off.
At that point grab on to that lil tab where it goes through the wastegate and move it up and down simulating the WG opening and closing. It should only rotate like 90 degrees and you should be able to feel when its seated down vs open. Report back what you find.
At that point grab on to that lil tab where it goes through the wastegate and move it up and down simulating the WG opening and closing. It should only rotate like 90 degrees and you should be able to feel when its seated down vs open. Report back what you find.
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V9RS (Mar 23, 2019)
Mar 24, 2019, 01:35 AM
#22
Newbie
Thread Starter
Problem solved!
I reset the ecu by disconnecting the negative terminal from battery and waited 10 minutes before reconnecting.
then did the relearn idle procedure (idle with no ac for another 10 minutes)
car now boosts to 21psi and holds stable with no spike!!
so, my assumption is that either it was the ecu disabling the boost control due to knock detection on a very very hot and hazy (wildfire) day and bad fuel or the BCS was broken but resetting the ecu was necessary after replacement.
The area I am based is going through a wildfire crisis (400+ pm2.5) with temperatures reaching and going beyond 40c, could this be the cause?
I reset the ecu by disconnecting the negative terminal from battery and waited 10 minutes before reconnecting.
then did the relearn idle procedure (idle with no ac for another 10 minutes)
car now boosts to 21psi and holds stable with no spike!!
so, my assumption is that either it was the ecu disabling the boost control due to knock detection on a very very hot and hazy (wildfire) day and bad fuel or the BCS was broken but resetting the ecu was necessary after replacement.
The area I am based is going through a wildfire crisis (400+ pm2.5) with temperatures reaching and going beyond 40c, could this be the cause?