Gamezilla

Unless someone else has a good explination.

Before I go into detail I have all the bolt ons, 850cc primaries, Power FC, and the car is converted to non-sequential twins.

Recently my turbo has been spooling up rather loudly (louder than my RB exaust) and has sounded almost like a jet engine (low rumble, not metal noise). My BOV has also been acting up, yet its not faulty. It will try and act sequential, letting off the first big hiss, followed by a longer lower and differently toned hiss.

Today my car was running fine. I was going through the engine bay checking to make sure the non-sequential job was done the way it should be. I drove up to auto express to pick up some oil (my car eats about .5 quarts of oil every 1k miles). On the way I made perfect boost. No issues. I go in, get my oil, come back up, start the car, no problems. Then when i pull out in front of traffic and give it a little gas, it happens. Boost builds up to .4bars, then it falls flat on its face. It bogs horrible, makes some weird noises (mostly puttering, exhaust sounding noises) and the boost bounces around between .45bars and .38bars. The car lurches and it feels like I'm driving a 50hp car. I've checked over every vaccum line, connection, etc 3 times over. Im pulling good vaccuum. The car drives fine at any rpm, except the second it tries to make over .4bars of boost. Until then all is normal. Its after that .4 that everything goes to ****. There isnt any smoke and the spark plug wires are in good condition and hooked up firmly. I dont think its spark since it idles like a champ. What could it be? Has one of my turbos kicked the bucket and its only a matter of time before it chews up the compressor wheel?

Oh ya - this is my daily driver. Without it I'm pretty much up a creek without a paddle.

SERIES7

Check all the couplers and make sure there aren't any slits in your lower and upper IC piping.

Gamezilla

Is this thing supposed to make a rattly noise like there's something loose inside of it?

SERIES7

That's prolly a one way check valve. Blow through it. If both airways are trapped, then get rid of it.

Snook

iTrader: (12)

thats a gas filter it shouldnt make any noise when you shake it and Id leave it there so your map sensor doesnt get fizacked.

try to redline the car at part throttle without boosting so you can eliminate an injector issue. Id check for even compression and change the plugs at the same time.

Gamezilla

Already ran the car up there in the rpms. Its for sure a turbo related issue. Why would the plugs stop working only under boost? Any why all of a sudden?

Snook

iTrader: (12)

the ignition is strained under boost
plugs can foul quickly and a coil can go out any second

take off the primary turbo inlet and check for shaft play if you think the turbos cant boost more than .4

SERIES7

Why would there be a fuel source going to the MAP sensor?
Eliminate all the possible simple culprits before you start tackling the tougher stuff.
Also, from the looks of that silicone hose going to your map sensor, it looks like there might have been a hose job done? If so, how long ago and have you checked any of those "other" check valves?

Gamezilla

gas as in vapor

SERIES7

Ah, so the hose coming from the Manifold to the map sensor has a clogged filter, perhaps?

Fumanchu

WTF is going on here? You actually know stuff about FD's? I thought you were just a postwhore

WaLieN

It could very well be the MAP sensor. Like I said in the other post -- use a hand pump and a voltmeter to check all of your solenoids/abv/crv/MAP/etc via the instructions from the fsm (www.iluvmyrx7.com). Have you noticed any smoking after you boost? Anyways, I hope you can find your problem -- turbo problems can be a pita.

cruiser

The thing in a picture must be a MAP sonsor filter. If its a check valve it would be stupid, as it would just let the pressure or vacuum to get into MAP sensor and then MAP sensor would hold that pressure/vacuum (sort of like record max value)

Try replacing that little filter. If it collapsed, it could give your MAP sensor bad readings and could contribute to your boost problems. Also check for shaft play.

Snook

iTrader: (12)

this forum = useless

speeddemon7

The piece thats circled in red is a check valve.Hence the directional arrow on it.Why the hell would a filter have a directional arrow on it? it wouldnt.Its a check valve. Check to see if air travels in the direction of the arrow.If it does great.Now check to see if air travels in the opposite direction.If it does.The check valve is fucked.If it doesnt its fine.

ps no fuel goes to this.its strictly vacuum.

Enconsiderate

hey i am suffering some of the same kind fo problems. such as

"Recently my turbo has been spooling up rather loudly (louder than my RB exaust) and has sounded almost like a jet engine (low rumble, not metal noise). My BOV has also been acting up, yet its not faulty. It will try and act sequential, letting off the first big hiss, followed by a longer lower and differently toned hiss."


does this info mean faulty turbos?

kwiktsi

Umm, no- read the shop manual- it is a filter. That is like asking why would a gas filter have an arrow on it also? Jeez- scary that some of you are actually working on your own cars. If you had any automotive knowledge, you would know the havoc a CHECK VALVE would wreak on a MAP sensor line.
Joe

edit- a lot of map sensors and important items have filters in line to prevent deterioration, clogging, etc.

Gamezilla

Car does smoke under boost. My primary turbo looks as if the oil return line has a bad seal. Not bad enough to worry about though. The smoke that comes out is mostly white (from running rich) and a little tint of blue. I have no cats or airpump, so that also can be attributed to the smoking. Oh, and I cant see the smoke through my mirrors. I have to have someone behind me to spot it. Its very hazy, dissipates pretty quick, and stays low to the ground.

Gamezilla

Okay, I went to mazda today. They couldnt find what part that was that I have circled on the first page. They called Mazda Headquarters, who also couldnt figure it out. They suggested a part that didnt look at all like the one I had (both in color and in shape). They're calling Japan to find out what part I need. Damn. All this for some tiny little piece of plastic.

speeddemon7

why not call ray crowe at malloy mazda.He would know what youre looking for.plus hes very good oon prices and also free shiping

maxcooper

I suspect that the bolts that hold the center section to the turbine housing on one of your turbos have come loose. The would explain the noise, and perhaps 0.4 bar of boost is enough load to make the turbine conact that housing to stop the turbo. Does it sound like you have an exahust leak at idle?

Before you pay for a new filter for the map sensor line, try blowing through it. If you can blow through it, you don't need a new filter. And by the way, has anyone ever heard of one of those going bad? I haven't.

-Max

Gamezilla

Doe it normaly rattle when you shake it? Mine does. And I dont think its a filter. It has an arrow on it. Looks more like a check valve.

Sonny

It's not a check valve. Check valves only allow air to pass in one direction. If you put one of those in front of the MAP sensor, the MAP sensor would never be allowed to see boost. The arrow on it just denotes which side should go towards the engine.

Sonny

Snook

iTrader: (12)

do you just pass up correct information on threads on purpose? its a ******* filter for the map sensor if yours is rattling then I dont know what the hell is wrong. just take it off and run the map sensor line straight there for a run and see if that fixes your problem. I doubt thats the problem though but also you dont want that thing to fall apart inside and clog up giving wrong readings to your map sensor.

maxcooper

It's a filter. I am certain. The arrow is so that you can install it the same way each time in the event that you need to remove it. Without the arrow, you might install it with the "dirty" side to the MAP sensor. A check valve on the MAP sensor simply would not work (think about it for two seconds!). I think mine has rattled when I checked it in the past. It seems to be a plastic body with a "puck" of metal wire (or something like that) in there as the filter media.

The most important point I would like to make is: That component has nothing to do with your car's problem.

-Max