Boost problem

mtet1101

New Member
Hi all, haven't had my gtir long so this is the first problem I'm having with it. It normally boosts at 0.9 bar running a mine's ecu with exhaust and air filter being the only mods. However yesterday it's developed a strange problem. It's only boosting up to 0.5 bar under full load but when It reaches 5500rpm it then changes to 0.7 bar :/ so far I have cleaned the plugs they're all ok, took apart the MAF and cleaned with brake cleaner, unplugged the ecu in an attempt to reset it incase it was in safe mode and blocked off the dv to see if that was releasing pressure. Checked for boost leaks aswell with no results :/ abit lost as where next to look can anyone shed any light on this for me?

Cheers Marc.
 

Gtirchris

Member
Hey buddy, have you done a fault code check?, does the car feel under-powered compared to what it did before the "fault" occurred?.
If it doesn't then it could be something as simple as the boost gauge is faulty be factory fit or aftermarket mate.
Does the car start, idle and run ok?, is it using excessive amounts of fuel??.
 

mtet1101

New Member
i havent done a fault code check, il do that tomorrow only just seen that on the how to. yes it definitely feels underpowered! its got standard boost guage and an aftermarket one so i can definitely see its underboosting then at 5500rpm its moved upto 0.7 but still not at 0.9 where it should be!it starts fine, the idle's not the best, tends to sit at 1500 but will then go down to 1000rpm. i suspect its overfuelling too is there anyway to lean it off abit without mapping?
 

red reading

Active Member
boost leak,knackered turbo my be detonation and the ecu is pulling the timing (that will show as a fault code on the ecu) are you using cheap petrol? and the car was set up for optimax?
 

mtet1101

New Member
only using v power, il have another look for boost leaks tomorrow and do a fault code check. fingers crossed the turbo isnt fucked although it does sound abit rough when its spinning after turning the engine off....
 

mtet1101

New Member
Nope have a HKS afr but not wired it in yet as the previous owner said it cause more problems than it was worth
 

SIR GTIR

Member
what exhurst is fitted i know from experience boost pressure wont get over 12psi and hold there
you maybe seeing the turbo spool but once spooled it cant maintain your boost pressure

correct me if im wrong just my theory
 
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