I'm starting to run very lean under boost, and only under boost. It runs rich the rest of the time. Once boost hits it goes from the blue leds to the red ones. I have 850cc secondaries, so that should take care of the fuel supply. What could it be?

-Ryan

 

air leak between turbo and throttle body?

 

Wouldn't an air leak cause it to run rich b/c of the metered air being let out, just like vent the factory bov to the atmosphere. Also an air leak would cause me not to get boost. It builds full boost. I'll check it out though.

-Ryan

 

Do you have an upgraded fuel pump?

 

no i don't have an upgraded fp. The stock should be able to supply enough fuel for .45bar boost (that is where i start to notice the lean condition, it does happen at lower boost though).

-Ryan

 

You may want to check your O2 sensor, mine gave me false lean readings when mine went bad.

 

maybe a bad boost sensor? so your ecu doesn't even think you are in boost? are you running an FCD? does the stock boost gauge move?

have you checked for engine codes.

what injectors are you running? never seen 850cc ones before in a 2nd gen...

at what rpm does it happen? can you make it go lean before 3800rpm? so boost at 3500? or only in higher rpm's?

 

They are rc eng injectors. Will happen at any RPM where >.4 bar boost is present. The factory boost gauge does not work, but when I turn the key on it will jump, but not all the way to the zero. More like between the 20 and the 0. It is actually running lean because i can feel it bog.

-Ryan

 

Hey there, neighbor! We are up here in Lawrenceville. I just wanted to let you know that the signal to the guage on the dash and the signal to the ECU are the same (Same wire, even). The dash guage is indicating that it is getting a signal. If it never goes above 0, most probably one of 2 things has happened: Either the vacuum line has broken/fallen off the sensor, or the sensor has failed. The sensor is on the front of the passenger side strut tower, and has a vacuum line to a hose connector on the ACV. I guess it could also be the ground to the boost sensor. Fix it, and your problem should go away, because the ECU will now know how much boost the turbo is generating.

Irv, Keith's dad

 

I'd say boging is caused by to rich, lean would be faster and more power. if you are running 850 injectors at .4 bar with no other major mods you are going to be running way rich. you probably killed your O2 sensor from running too rich.
so that might be your problem

however your stock gauge should work. as I mentioned before and keith's dad said check your boost sensor. if this is not working it will definatly run lean under boost.

take your pic either way could be right.

what else do you have that requires 850cc injectors? do you have any way to tune them?

 

I've got the 850cc injectors b/c the old engine that was in the car had a ported turbo and streetport. I can tune them with my s-afc.

Also a sidenote:
-I had recently broken the fitting on my air bypass solenoid (the fitting that goes to the bac), and I gooped it back on. Well of course it broke again, so I decided to try to just stick the hose that goes from the intercooler to the air bypass solenoid directly onto the one that comes from the bac (which is supposed to go to the air bypass solenoid. This caused my idle to fluctuate between 1000 and 1500 rpm and also made me start backfiring at high rpms. Then I decided to just unhook the hose from the bac to the air bypass solenoid, and leave it undone. This was worse...no idle. Then I just plugged the hose that goes to the bac, and it idles normally, but still runs lean (according to the a/f meter). Also the vaccum hose on my boost sensor does not go to the acv but to my bac instead. Can i use a boost sensor off of an n/a car. Also what readily available (i mean very easy to find and cheap) o2 sensor can I use?


-Ryan

 

bump

 

What you saw with the BAC hose connections was actually normal. I say that because, although the connection looks like it goes to the BAC, it is actually a connection into the initake manifold, shared by the BAC. The result, any connection bypassing the air bypass solenoid valve is an automatic vacuum leak! Your car did all the normal stuff that a vacuum leak causes.

As far as the vacuum hose from the pressure sensor, does it go to a port directly underneath the BAC? If that is the port we are talking about here, it should go to the Air Bypass Valve (Stock Blow-off valve). Possibly, the hoses got swapped? (ACV to blow-off, BAC to boost sensor.) If the hoses did indeed get swapped, check to see if the hose to the blow-off valve has a white dot on it. This would be near the ACV. If it does, swap the hoses back, you need this (Restrictor) on the Boost Sensor. Otherwise, I see no problem with the hoses reversed, although I have not tried it.

No, an n/a boost sensor will not work on a TII. They are different.
If you want to do a voltage check on the TII boost sensor, I can give you a test point and voltages. Let me know.

Autozone carries a Bosch 02 sensor for $35.99. RP carries one for $40. You can get a universal replacement from Autozone for $17.99, but you will need to splice it in, and I do not know if it will handle the hot Rotary or not.

Peace. Irv, Keith's dad