Low Fuel Trim At 139% Won't boost past 11psi

[Matrixhunter]

So here is the problem-- 6 bolt 1992 TSI FWD

My fuel trims need some help the low trim is at 139% but the other two are at 100%??

The problem that i seem to be having is that the car cannot boost past 11psi and it looks like it fluctuates a bit from 10-11psi back and forth once it reaches this boost level.

I double checked all my connections and there should be no boost leaks.

However the only thing i can think of is either the wastegate arm is not working correcty or there is some sort of boost leak that is stopping me at 11psi. I will do a proper boost leak test tommorow but I just though i'd get some opinions on this.

Also I'm assuming that the low fuel trim would have something to do with the leak if there is one?? Engine is the car is a new jdm with cylone intake and i have a highly ported 14b.

Thanks

 

[Rob10_99]

139%, is that even possible?!

buy bigger injectors!

 

[maddmaxx]

After I did a turbo swap on my car, my CEL came on. I hooked my logger to it, and it said the exact same thing. Fuel Trim (bank 1) error. Turned out to be the upstream O2 sensor. It was flatlined no matter what throttle I was at. If I were you, I'd hook a logger to it and see if it's running really lean (caused by the bad O2 sensor). If it's running extremely lean, then it would make sense that you can't boost past 11psi because your not getting enough fuel. Just a suggestion

 

[Matrixhunter]

I just checked the o2 and this is what i am getting at idle it reads 0 volts but the o2 seems to work when i add some gas it does give back some readings. What are considered normal 02 readings at idle? i have a denso o2 sensor which doesn't have more than 10,000km on it?

 

[EuroGSTSpyder]

I had 137 on my LFT and it all went back to 100 when I changed the O2 sensor.

 

[Matrixhunter]

I will change the o2 in that case but in your opinion would the o2 prevent that car from boosting past 11psi? even when the other fuel trims are 100

 

[Matrixhunter]

Problem solved after the boost leak test turns out it was a huge!!!!

 

[EuroGSTSpyder]

did it solve the boost thing or both?

 

[DROOPY209]

Well did it fix both things? How big was the boost leak? Where was it at? I have the same exact problems as you did.

 

[tom04841]

Well did it fix both things? How big was the boost leak? Where was it at? I have the same exact problems as you did.

Droopy, you have a boost leak. Find it, fix it, and you'll be fine.

 

[Matrixhunter]

It did not solve the fuel trim but i am certain that the trim has to do with the o2 sensor but the car boosts amazing never had it boosting so smooth. The Leak was right on the coupler (reducer) that joined my metal upper intercooler piping to the stock intercooler. Only thing i never changed in the car really.... before i changed it to a new one couldnt pressurize the car to even 5psi. Holds good at 20psi now.

 

[Matrixhunter]

Also incase anyone else is wondering make sure you don't have your boost controller connected with a T in the bov line. Just connect it from the J pipe nipple directly to the actuator, i was shocked how boost/throttle response improved.

 

[4g63t]

my low trim is also at 139.. and I have 780cc inj... and my 02 is brand new via wideband..