ok so i decided to start messing with the new ugly beat down fd today. start it, let it warm up, look at pfc commander. 400mmhg at 900 rpm. not bad i suppose, i then decide to pull the breathers off, the bottom one looks normal, the top on the other hand is kinda melted and completely engulfed in black soot. so i open the throttle body by hand and the weirdest thing happened, the bottom one is sucking and the top breather inlet is blowing air and soot out. i guess the turbos are bad? maybe not hooked up correctly? was hoping that these would be good as they are supposedly 99 enfini twins. either way, i just figured i would ask/

 

btw, i trailered it home instead of driving, i plan on replacing the fpd, the cooling fans and going through the vacumn hoses. the motor is said to be a 3mm seal with a street port.

 

By breathers I'm assuming you mean air filters, correct?

When you open and the close the throttlebody butterfly plate, do you hear any surging coming from your turbos (fluttering sound). The reason I ask is because turbo surge occurs when boost from your turbos have no where to go when the throttle plate closes, so it goes backwards through your compressor and surges.

Are the twins still sequential or have they been modded to be non-sequential? If they are still sequential, then the first thing I would check is your charge relief valve and charge control actuator because you mentioned that it was your top air filter which is the one that goes to the rear turbo. The charge relief valve is supposed to be open during prespool, so I would definitely check to make sure that is open. If you are non-sequential, then check the bypass valve and make sure that's working properly.

Also, just to be sure, inspect both turbos from the compressor wheel to make sure they spin properly and don't have excessive play.

 

i do mean filters, sorry about that, i believe these turbos are still running sequential as the previous owner mentioned nothing of mods done to the turbo. the b.ov. is working and vented to atmosphere. i guess i need to pull the tubes going down to the turbos and inspect them the right way. just dont understand why one would be blowing back and that jacked up. will try to get pics and some vid of this.

 

weird, must see post video.

 

working on it, converting hd sucks.

 

well if its still sequential the secondary boost control valve or whatever its called in the j-pipe coming up from the back turbo to meet with the y-pipe could be open. being that the rear isnt spooled till 4500ish rpm anyway the front is sucking in air pushing past the open valve and out the secondary turbo's inlet piping.... fwiw

z

 

another possibility

 

The valve that you are talking about is the CCA (Charge Control Actuator). If it was stuck open with everything else working properly, it wouldn't just boost from the front turbo through the Y-pipe to the rear turbo compressor housing, through the compressor wheel, and then through the intake pipe. Although secondary boost doesn't kick in until around 4500ish rpm, that doesn't mean that the secondary turbo isn't spinning. Before 4500 rpm, the CCA is closed, the CRV is open and the secondary turbo pre-spools and just bleeds out through the CRV.

I can see your scenario happening IF for some reason, the secondary turbo was seized, then there wouldn't be any opposing forces of air, that's why I said check the condition of the turbos in my previous post.

I still say check the CRV (the second blow off valve looking thing closer to the rear, which has a very different function from a blow off valve) and then go on from there.

 

pulled stuff off today, made a discovery. their are three lines that hook into that pipe that goes to the filter, the one from the compressor inlet, the one that goes to b.o.v. looking thing and then one that is close to the motor, the one close to the motor is the one blowing air out. the others are doing nothing.

 

is that emissions related?

 

Two suggestions for you:

1. Start reading the FSM, TSB's, Service Highlights for the FD
2. Open up your pocketbook, don't plan on sending your kids to college or taking lavish vacations unless you lose the car



j/k, just do your homework, these cars are take a very special kind of love/attention. Have fun, I don't know what I'd do w/o my FD, I love the car.