[Kikla]

So the other day i was doin a pull and when i tried doin another 1 the car wouldn't go past 10psi and ran really rich 10AFR. Car runs perfectly fine regular driving. I did a boost leak test and there is no leaks. When on WOT the car runs heavy. Tried disconnecting the battery and nothing. Changed spark plugs still nothing. No check engine and vacuum is at 20. Im running a Gt3076r with precision 39mm waste gate dyno tunned on e85, walbro 450. Car ren 20psi.

 

[Kikla]

Bump

 

[AlmightyFork]

Bump

Boost control? What lb spring in your wastegate?

 

[Kikla]

Im running a manual boost controller and im not sure what spring is in the wastegate. Most likely the spring that the wastegate comes preinstalled from manufacturer. Cant remember. The car will boost more when i turn up the boost but it still runs bad

 

[AlmightyFork]

I'd check out the reply in this recent thread - Boost all good under 15psi only

 

[Kikla]

The thing is that the car doesnt sputter or misfire or anything. It runs heavy like its working extra hard to make boost and i havent touched anything , it just happened out of nowhere

 

[AlmightyFork]

AFR got rich and power loss was observed. To me, it's worth troubleshooting spark without any other information. Check engine light by any chance?

 

[Kikla]

No check engine and i did change and gapped the spark plugs. I was thinking mabie the wastegate is stuck open, but then i dont hear exhaust threw the dump tube and its not stuck close because no overboost. Called my tuner asking for my dyno file so i can mabie reflash the ecu. But he insisted its a boost leak. I boost leak test the car and i swear there is no leaks. This is so weird

 

[AlmightyFork]

No check engine and i did change and gapped the spark plugs. I was thinking mabie the wastegate is stuck open, but then i dont hear exhaust threw the dump tube and its not stuck close because no overboost. Called my tuner asking for my dyno file so i can mabie reflash the ecu. But he insisted its a boost leak. I boost leak test the car and i swear there is no leaks. This is so weird

What did you pressurize your system to? How long did it hold this PSI? Have you considered having a friend help you listen?

Otherwise, spark still seems to be the best place to continue your investigation. Especially since you just made a change there. If it was a sensor or solenoid, you'd have a CEL most likely. Since you're running rich, I wouldn't spend a lot of time investigating fuel.

Remember your triangle. Fuel, air, spark. Confirm all 3.

 

[Kikla]

I pressurized it to about 25psi and it started to leak out the oil cap and throttle plate and it slowly went down other then that nothing else leaked. Im goin to try spark plugs, spark plug wires and ignition coil. Thanks for the help

 

[Kikla]

So i ren straight off the wastegate and the car ren nicely with perfect afr but only pushed 10psi so im guessing the spring is 10psi and my boost controller might be what is causing all this

 

[AlmightyFork]

So i ren straight off the wastegate and the car ren nicely with perfect afr but only pushed 10psi so im guessing the spring is 10psi and my boost controller might be what is causing all this

Glad you're getting it figured out. I actually had to look up other cases of an MBC failing. They are so simple I couldn't imagine how they would break.

 

[Kikla]

Figured out the problem. My catalytic converter clogged my exhaust flow.

 

[Pwnr]

I had a clogged cat before too. It’s hard to diagnose. Turbo cars need an open exhaust to function properly.