Gilhuly Posted February 4, 2008 Report Share Posted February 4, 2008 +1. When I did my PCV with no symptoms prior other than mediocre boost my car was a totally different animal afterward and I suspect it had to do specifically with the area mentioned below, though I never knew for sure. None of the major PCV stuff turned out to be clogged and I had done my vac lines prior as well.Hey, Check the PCV where it comes into the intake is all I am saying.. I have had similar effects to what your talking about when messing with it and thats why I am suggesting it. -Your PalFishey Link to comment Share on other sites More sharing options...
Seagrams Posted February 4, 2008 Author Report Share Posted February 4, 2008 Stupid question perhaps - but is the lower BCS hose (18) connected to the underside nipple at the top of the inlet hose, and have you checked to confirm it's not restricted? If the BCS can't vent, you won't get the boost increase...Yea, My setup is slightly different than the one posted, (three vertical nipples will post pic later today hopefully) but that line, which is the middle of the three and goes to the intake piping post MAF is hooked up and clear (when i'm not running the MBC that is).PVC is becoming more of an interest to me now. I talked to my indy about it cause he services it regularly and I don't think it's shot yet. i'm not getting positive pressure coming out of the engine did the paper test over the oil filler cap (which is good, no air blowing out of the dipstick). But i do have a slow leak around my RMS which i've read is usually/can be caused by a malfunctioning PCV system so i wonder.......Tell me more Gilhuly, what turned out to be the problem if nothing was really blocked up? But it still come down to the fact that with the MBC i get boost out the ying yang, so i'd think if there was something physically limiting boost (like a blockage or something) it would affect the MBC. Unless of course it's actually set to open at 15 psi, but because of the problem i'm having it's only showing 10, (like i'm overcompensating or something). Link to comment Share on other sites More sharing options...
lookforjoe Posted February 4, 2008 Report Share Posted February 4, 2008 Yea, My setup is slightly different than the one posted, (three vertical nipples will post pic later today hopefully) but that line, which is the middle of the three and goes to the intake piping post MAF is hooked up and clear (when i'm not running the MBC that is).PVC is becoming more of an interest to me now. I talked to my indy about it cause he services it regularly and I don't think it's shot yet. i'm not getting positive pressure coming out of the engine did the paper test over the oil filler cap (which is good, no air blowing out of the dipstick). But i do have a slow leak around my RMS which i've read is usually/can be caused by a malfunctioning PCV system so i wonder.......Tell me more Gilhuly, what turned out to be the problem if nothing was really blocked up? But it still come down to the fact that with the MBC i get boost out the ying yang, so i'd think if there was something physically limiting boost (like a blockage or something) it would affect the MBC. Unless of course it's actually set to open at 15 psi, but because of the problem i'm having it's only showing 10, (like i'm overcompensating or something).Did you ever try loosening the downpipe @ the turbo to see if that made a difference?If you're not sure what pressure the MBC is set to, you may want to manually pressure test it to confirm - if as you suggest it could be set higher than the ten you're getting, then the problem must be more basic - so I'd still want to vent the exhaust @ the turbo/downpipe to rule out exhaust restriction. Link to comment Share on other sites More sharing options...
Seagrams Posted February 4, 2008 Author Report Share Posted February 4, 2008 Did you ever try loosening the downpipe @ the turbo to see if that made a difference?If you're not sure what pressure the MBC is set to, you may want to manually pressure test it to confirm - if as you suggest it could be set higher than the ten you're getting, then the problem must be more basic - so I'd still want to vent the exhaust @ the turbo/downpipe to rule out exhaust restriction.No. I actually totally forgot about that . How much should i loosen it? just a crack or maybe back the nuts off like an inch or so? Is there anything i want to be particularly mindful of like the fact that i'm venting hot exhaust gases all up in my engine compartment?In order to test the turbo, it needs to be warm, but i'd need it to be cool while loosening the downpipe, so should I loosen it cold then let it idle with the hood up to warm it up? Might seem like a dumb question but I'd imagine that it'll be loud as balls, and would like to keep running time (the noise citation window) to a minimum.Hell it's just 3 bolts right? I can prolly knock this out tonight. Link to comment Share on other sites More sharing options...
theForgottenone Posted February 4, 2008 Report Share Posted February 4, 2008 No. I actually totally forgot about that . How much should i loosen it? just a crack or maybe back the nuts off like an inch or so? Is there anything i want to be particularly mindful of like the fact that i'm venting hot exhaust gases all up in my engine compartment?In order to test the turbo, it needs to be warm, but i'd need it to be cool while loosening the downpipe, so should I loosen it cold then let it idle with the hood up to warm it up? Might seem like a dumb question but I'd imagine that it'll be loud as balls, and would like to keep running time (the noise citation window) to a minimum.Hell it's just 3 bolts right? I can prolly knock this out tonight.Let it cool down (engine) first and spray some WD40 to loosen those DP bolts. They can be rusty and hard to remove.Afterward, you can take a drive around the neighborhood and you will know right away if it make a big difference. Link to comment Share on other sites More sharing options...
lookforjoe Posted February 4, 2008 Report Share Posted February 4, 2008 No. I actually totally forgot about that . How much should i loosen it? just a crack or maybe back the nuts off like an inch or so? Is there anything i want to be particularly mindful of like the fact that i'm venting hot exhaust gases all up in my engine compartment?In order to test the turbo, it needs to be warm, but i'd need it to be cool while loosening the downpipe, so should I loosen it cold then let it idle with the hood up to warm it up? Might seem like a dumb question but I'd imagine that it'll be loud as balls, and would like to keep running time (the noise citation window) to a minimum.Hell it's just 3 bolts right? I can prolly knock this out tonight.What he said. Spray down the nuts/studs.I backed the nuts off about an inch or so: on mine, the lower stud came out with the nut, no big deal if it does, just don't burn yourself putting it back. If your downpipe support bracket is still attached (to the Angle drive casing) you'll need to wedge the pipe/turbo flange apart, I did. EDIT: forgot, this is your 850 not your AWD. I did mine with the engine warm, but after sitting for about 10mins.It's not really so very loud, since it's not wide open. Link to comment Share on other sites More sharing options...
Gilhuly Posted February 4, 2008 Report Share Posted February 4, 2008 See, that's the thing, I never did definitively figure it out. What i do know is that when I replaced all my PCV components and reassembled the car It ran like a T5 oughta. I did break the hoses that come over from the intake on disassemby and didn't pay a hell of a lot of attention to them. I may have had a garden variety vacuum leak that only affected boost because the car ran fine otherwise.Yea, My setup is slightly different than the one posted, (three vertical nipples will post pic later today hopefully) but that line, which is the middle of the three and goes to the intake piping post MAF is hooked up and clear (when i'm not running the MBC that is).PVC is becoming more of an interest to me now. I talked to my indy about it cause he services it regularly and I don't think it's shot yet. i'm not getting positive pressure coming out of the engine did the paper test over the oil filler cap (which is good, no air blowing out of the dipstick). But i do have a slow leak around my RMS which i've read is usually/can be caused by a malfunctioning PCV system so i wonder.......Tell me more Gilhuly, what turned out to be the problem if nothing was really blocked up? But it still come down to the fact that with the MBC i get boost out the ying yang, so i'd think if there was something physically limiting boost (like a blockage or something) it would affect the MBC. Unless of course it's actually set to open at 15 psi, but because of the problem i'm having it's only showing 10, (like i'm overcompensating or something). Link to comment Share on other sites More sharing options...
Gilhuly Posted February 4, 2008 Report Share Posted February 4, 2008 OK I was just looking in Vadis and it states that the turbo charger control valve uses three inputs for pressure controlMAFThrottle Pos sensorRPM sensorIf you assume that the throttle pos sensor and the rpm sensor are OK and based on your variables with the MBC don't you think its possible that you are either getting bad MAF signal to the ECU or the ECU is screwing up.But maybe not.I think the TPS and RPM signals are used to limit boost mostly (in 1st). The tranny control module limits boost(in 1st, reverse ,winter mode). The knock sensor can limit boost, the coolant temp sensor can limit boost. Boost pressure is monitored by a calculation off the MAF, though, not any kind of pressure sensor. If you did have limited flow through your cat and your system is sealed up tight, intake air is limited and the MAF is calculating (correctly) a limited amount of air coming in and telling the ECM as much. The ECM limits boost based on this correct calculation of moderate amounts of air passing the MAF.I think you either have a bad MAF signal or you have a plugged cat. Link to comment Share on other sites More sharing options...
sconeman Posted February 5, 2008 Report Share Posted February 5, 2008 Hey have you been able to test your car with the DP loosened yet? Curious how that's gonna turn out. It must be the year for annoying boost issues as I'm having one myself. Link to comment Share on other sites More sharing options...
Seagrams Posted February 5, 2008 Author Report Share Posted February 5, 2008 Hey have you been able to test your car with the DP loosened yet? Curious how that's gonna turn out. It must be the year for annoying boost issues as I'm having one myself.havent' doen that yet, it's wet and rainy. will let you know how it turns out. Until then maybe check your BCS (can't tell from the sig if you're running an MBC). I just put up a thread about what's inside the BCS, how it works and a decent way to test it. check it out. Link to comment Share on other sites More sharing options...
sconeman Posted February 6, 2008 Report Share Posted February 6, 2008 havent' doen that yet, it's wet and rainy. will let you know how it turns out. Until then maybe check your BCS (can't tell from the sig if you're running an MBC). I just put up a thread about what's inside the BCS, how it works and a decent way to test it. check it out.Cool thanks. FYI I seperated my DP tonight and it made no difference but it was a little louder So I guess it's not the cat for me. My car won't boost above 8 should be hitting 14 at least. No mbc btw. I am methodically plowing through all the fixes and tests so I'll probably test the BCS soon gotta get a test light first. Haven't pressure tested the system yet either.I won't jack your thread. If I don't get some answers soon I'll probably start one of my own. I want that extra psi. Link to comment Share on other sites More sharing options...
Seagrams Posted February 6, 2008 Author Report Share Posted February 6, 2008 Cool thanks. FYI I seperated my DP tonight and it made no difference but it was a little louder So I guess it's not the cat for me. My car won't boost above 8 should be hitting 14 at least. No mbc btw. I am methodically plowing through all the fixes and tests so I'll probably test the BCS soon gotta get a test light first. Haven't pressure tested the system yet either.I won't jack your thread. If I don't get some answers soon I'll probably start one of my own. I want that extra psi.If you don't have a test light you can still see if the BCS is working (assuming it is getting electric current, but that's what the test light is for). Just unhook your BCS (i shoulda put these pic up too), get some electrical connectors the ones that look kinda like a plug (you know that the flat connector fits into) and run two wires from the BCS connection and touch the ends of the wires to your battery terminals. You should hear a click. That means it works. Then go on to seeing if the BCS is actually receiving a signal from the ECU. Link to comment Share on other sites More sharing options...
sconeman Posted February 6, 2008 Report Share Posted February 6, 2008 Then go on to seeing if the BCS is actually receiving a signal from the ECU.How do I do that? Link to comment Share on other sites More sharing options...
Seagrams Posted February 6, 2008 Author Report Share Posted February 6, 2008 How do I do that?unhook the wires from the BCS and hook a test light up to the metal connectors in the clip. Then turn on the car, put it in drive and step on the brake like your life depended on it and step on the gas to get into the boost. While your doing this, have another person holding the test light in the connector watch for it to turn on and off rapidly. If the light flashes on and off while you're "boosting" it means that the ECU is sending an electrical signal (duty cycle) to the BCS. easy as bananas Link to comment Share on other sites More sharing options...
Pops Racer Posted February 6, 2008 Report Share Posted February 6, 2008 Mmmmm, bananas. Seagrams you rock, you are going above and beyond here. I am becoming a BCS expert! Thank you for your insight. Link to comment Share on other sites More sharing options...
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