High boost/low idle after BOV Install

[killinlonelinez]

Ok ive been searching and browsing for 3 hours now and i have found similar posts with similar poblems but not quite the same, and i havent found an answer in any of the so here it goes.

Today i installed a Greddy Type RS BOV and a Dejon UICP. After the install i made sure everything was tight blah blah blah im kinda anal about that s***. I started the car and first noticed that it idled kinda funny like really low 4-500 rpm low. Still wanted to see how it would drive so i took it out for a spin and when the turbo finally spooled up it jumped to 25psi when b4 the install it was around 12-13. i immediately turned around and went back home. After that i started paying closer attention to my gauges and noticed that it was running lean as hell. i got back to my garage rechecked all the hoses everything was good. anyways i said screw i and put the stock UICP and BOV back on and everything returned to normal. WTF oh well i think its the bov any ideas? how do i fix it

 

[93_tsi_fwd]

Is you bov recirculated or vented to atmosphere? can you post a picture of it ot installed.

 

[crimsondragon]

Hm try resetting your ECU after the install.

 

[killinlonelinez]

wel m in the newbie forum so obviously im newto DSM my BOV is not recirculated but all the holes and lines were pugged i cant get pics up right now. Hw do you reset the ECU?

 

[crimsondragon]

Well first recirculate it. I think you're letting too much air in causing a lean condition. To reset your ECU, unplug the battery for like 5 minutes or until the car is electrically dead.

 

[toojung2die]

Well first recirculate it. I think you're letting too much air in causing a lean condition. To reset your ECU, unplug the battery for like 5 minutes or until the car is electrically dead.

Actually, venting the BOV causes an over rich condition because air the MAF has measured and adjusted for is vented and lost. Less air + more fuel = rich. Whatever, recirculate the BOV, don't vent it. It's a good idea to reset the ECU as described above so the it has learn the new conditions. It's also a good idea to buy an OBD-II code reader so CEL's that can be caused by new mods can be diagnosed and fixed. My old dwell-tachometer is gathering dust but the OBD-II reader gets regular use. More boost used to give me vacuum hoses blowing off and causing CEL's pretty regularly.

 

[killinlonelinez]

Ok what wouuld i needt vent the bov instead of recirc? i also why would it be running lean if is supposedly getting less air i know my a/f gauge is working properly?

 

[whiteflash]

I had the same problem when i installed my RRE UICP with 1g bov. The boost is going so high because the stock one leaked at 12-13 psi and wouldnt let it go any higher, but now since you have a bov that doesnt leak it will keep building boost. Get an MBC and set the boost to where you want it.

 

[crimsondragon]

Actually, venting the BOV causes an over rich condition because air the MAF has measured and adjusted for is vented and lost. Less air + more fuel = rich. Whatever, recirculate the BOV, don't vent it. It's a good idea to reset the ECU as described above so the it has learn the new conditions. It's also a good idea to buy an OBD-II code reader so CEL's that can be caused by new mods can be diagnosed and fixed. My old dwell-tachometer is gathering dust but the OBD-II reader gets regular use. More boost used to give me vacuum hoses blowing off and causing CEL's pretty regularly.

It depends on the BOV. If it's crap, it'll leak air in during vacuum.

 

[No_Skillz]

A BOV and UICP does not control the amount of boost you run when properly installed, so you need to check how you set everything up. Where did you connect the vacuum fitting coming off of the Greddy RS? Did you BLT? Do you have an MBC? If not, check all the vacuum lines going from the turbo the BCS. Anything ripped will be easily found with a BLT. How do you know that you were running a little lean with your a/f guage? At partial throttle the o2 sensor cycles, not the mention that if it's not a wideband it doesn't give you any useful info (ricer mod).

I'm guessing that one of the lines going to your BCS is ripped, thereby causing no boost control. You never noticed it with your old plasitc BOV because that thing sucks and can't hold more boost than ~12psi. Check all the stuff I suggested, clean up your boost leaks (of which I guarantee you will have many - personal experience talking), and recirculate that BOV. You will need a recirculation fitting and attach a hose from the BOV to that big hole in your intake pipe.