Running Rich & boosting problems

[Tsi_Twaan]

91 tsi, replaced the ecu it was fried and also had to replace the maf it was also bad. that fixed my stumbling problem at crusing speeds on the high way. But its still running super rich. The o2 sensor in good I just tested it along with the coolant temp sendor to the ecu. Any ideas??? Now for the boost problems, I just had a 3" cat back done along with a 2 1/2" test pipe and down pipe. I was running around 14-15 psi with some boost creep before with the stock exuast. now with the exuast done i'm only boosting 11 psi and the boost will climb with high rpm in higher gears to around 13 psi or so. it does not matter how high the boost controller is set at. I've tried a different controller and the waste gate tested out good. my brain is fried trying to figure this one out. good luck to anybody how has any ideas

 

[1992awdlaser]

Boost leak test?

 

[8urwrx]

Id say boost leak test also. Maybe your knock sensor is on its way out and is causing your ECU to dump fuel to control knock. With the boost issue id say its still creeping. Port out your o2 housing and the turbo itself and it sould help out some.

 

[Tsi_Twaan]

i havent yet because i've been trying to chase down the rich running issue. #1 injector o-ring was leaking so I just got done replacing them. I also just replaced the o2 sensor and that help a little but i hooked it up to the emmissions machine and i'm at 2000 HC and my CO was at 3.0% and with the o2 I got it down to 1.5%. I realize that my readings are going to be higher because of the cat not being in but this is crazy. its a fat pig and killing my brain trying to figure this one out

 

[1992awdlaser]

A boost leak can cause a rich condition.

 

[Tsi_Twaan]

This is true. Im going to make a boost leak tester tomorrow and see what I can find. i would almost hope that I have a leak so i can keep moving forward. Im also going to do a compression test and leak down test to just eliminate that motors bad

 

[jking29]

Maybe your knock sensor is on its way out and is causing your ECU to dump fuel to control knock.

The knock sensor will not cause your ecu to dump fuel, it will however, make the ecu pull timing back.

 

[jking29]

This is true. Im going to make a boost leak tester tomorrow and see what I can find. i would almost hope that I have a leak so i can keep moving forward. Im also going to do a compression test and leak down test to just eliminate that motors bad

My guess is you will find some big boost leaks.

 

[Tsi_Twaan]

does anyone actually sell a boost leak detector or does everyone just make theres

 

[1992awdlaser]

Mach V Leak Tester