Boost/Fuel cut woes.

[MKIIITurbo88]

Hello all -

I have recently ran into an issue on my MKIII 7M-GTE. Previously, I was running around 10/11 PSI without issue. No fuel cut, 13:1 A/F, and consistent boost. Out of nowhere, I am not only able to hit around 6 psi, and if it increases any higher, I hit fuel cut. I have a EBC set to 11, and I have a mechanical gauge to see actual manifold pressure, regardless of the electronic boost controller read out. Once my mechanical gauge hits ~6, It feels like someone hit me in the back of the head when fuel cut hits.

I am looking for some diagnostic help - my initial thought was that I might have a boost leak, and the MAF thinks I am over boosting, thus cutting fuel. Does this scenario make sense? I am still running the stock rubber boost hoses from turbo - intercooler - intake.

Thanks for any advice.

 

[Dan_Gyoba]

Look for boost leaks. This is the most likely explanation.

 

[IndigoMKII]

Uh? What the hell? 13:1 afr? If your car is in stock form and running 13:1 afr, you got bigger issues than a boost leak. Normally under WOT, these cars are deep into the 10's for the afr.

 

[Mikael_7m]

13:1 seems quite dangerous under WOT

 

[gsxr141]

check for boost leaks. start with the hose right off the turbo. mine literally fell apart in my hand. after that check all the clamps. what you're describing absolutely sounds like a boost leak.

 

[MKIIITurbo88]

Thanks for the replies - I am going to dig into it tomorrow; I'll let you guys know what I find. 13:1 isn't WOT/full boost, It's my steady state. I do see around 11 at WOT. I was looking at the averag on my logger from a short run.

thanks,

 

[jetjock]

13:1 steady state is rich. Should be stoich. Doesn't really jive with an induction leak but I'd fix that first.

 

[MKIIITurbo88]

Found the problem - The No.1 hose from the turbo outlet had a good size blowout. Needless to say, I am in search of a new Charge hose; I've added a wanted thread, but have had little to no luck finding one through several venues. Any other ideas?