12leavu

iTrader: (1)

my car is making only 5psi all the way through the rpms. vacuum hose to gauge is not kinked either. i ran hose to the capped fitting on the upper intake

rynberg

http://www.autosportracetech.com/RX-...leshooting.htm

12leavu

iTrader: (1)

thanks i will check that link. i just went and bought a new autometer gauge and switched it with the old junk gauge i had. its showing 7 psi all the way thru the rpms spikes to 8 or 9 between shifts. (automatic)

rynberg

Sounds like the pill is missing in the wastegate line or the solenoid is unplugged.

12leavu

iTrader: (1)

thats a possibility. the car just had a new wiring harness installed before i bought the car along with a new transmission. they had alot of stuff apart im sure, they may have missed something. i will check that pill your talking about. also thanks for that link it will be a major help. ............ could it be possible that that solenoid went bad? i will check connection tomorrow and look for that pill.(even though i dont know what the "pill" looks like.)

Sr20fd3st

yea ~7psi is the wastegate spring minimum. if the solenoid is stuck closed you will have this. if it is stuck open you will overboost. If it's closed in the unplugged state it could easily be that. a missing pill woul also let extra boost into the wastegate making it open sooner so it could be that as well, but since you said you had the harness messed with id check that solenoid first.

the pill looks like an tiny round cylinder the size of a bb with rounded corners and a hole in it.

12leavu

iTrader: (1)

thanks i just read about those pills on that link in this thread. i will check that tomorrow when i get off work. according to the diagram, it looks like the pills are in the vacuum lines going to the actuators. i will check that. i hope its that easy. this car is pretty much flawless other than the boost problem. thanks guys

Sr20fd3st

might be a slight pain in the *** to get to, but yea it's that simple.

12leavu

iTrader: (1)

ok guys. i checked the vacuum line. the pill is there. could someone tell me the location of the wastegate solenoid? thanks

12leavu

iTrader: (1)

i think that i found the solenoid on the front of the upper intake on the right side of the two solenoids mounted together. if so it is plugged in. so i guess i will see if there is a way to check it before i go buy a new one from mazda for 160.00

rynberg

Make sure the pre-control and wastegate solenoid plugs aren't switched. And yes, they're the two solenoids up front.

12leavu

iTrader: (1)

thanks i will go check that now..

12leavu

iTrader: (1)

you are a genius! now i have uncovered another problem.....way too much boost. when i pulled out and laid it down it instantlly pulled to 13 psi. and was climing fast. i got out of it and drove it home. i remember you asking if it was hitting fuel cut. well now it is. i guess a boost controller is my next purchase.?? thanks alot for your advice

Sr20fd3st

what are your mods?

dgeesaman

iTrader: (7)

Make sure the vacuum lines leading from the wastegate and precontrol solenoids have NO LEAKS all the way down to the actuators and turbos.

However, since you were getting the normal 8psi with the solenoids not connected, I'll bet you have an open exhaust. If that's true you need to research the subject of boost creep. It's in the FAQ. Long story short, your exhaust has opened up so much that the opening in your wastegate needs to open up too. Boost controller doesn't solve it - you must increase restriction in the exhaust or grind out the wastegate.

Sr20fd3st

theres some thing some guy was selling on here, exhaust restrictor plates. i think that defeats the purpose of puting on an open exhaust...but i guess it works. it was expensive for a piece of sheet metal though. try just buying a metal flange somewhere to put between the pipe that has like a 2 Inch I.D. or getting some sheet metal and cutting one to the shape of the flange of the pipe and just making the I.D 2 inch... better than going through the hastle of removing the turbos, taking the housings apart that never want to come apart with ease( atleast for me) and grinding out the wastegate like i did.

12leavu

iTrader: (1)

i bought the car with a full hks exhaust including downpipe. when i put it on a lift it looked like they had welded a small convertor in just before the muffler. i assume its a high flow convertor. im not sure on the diameters but its necked down and back up. thanks for the info. i will do some research on boost creep.

***would putting the silencer back in the muffler be wise to do. it has the 2 holes in the side of the exhaust tip for a silencer. i dont own a silencer but a friend of mine with a supra with same exhaust has one i can use.

rynberg

better to just install a boost controller. For the moment, you can just remove the pill from the line or unplug the wastegate solenoid to keep you at 7-8 psi.

Sr20fd3st

boost controller wont neccessarily stop boost creep, unless maybe a real nice electronic one that can react fast enough to do the job. it will keep you from simply overboosting though. problem is that boost creep comes up so fast that a boost controller cant always stop the boost fast enough. I dont think a silencer will create enough backpressure to resolve the boost creep. port your wastegate or restrict your exhaust

rynberg

He said there is a cat installed in the exhaust...therefore it is not boost creep.

12leavu

iTrader: (1)

well restricting the exhaust will be a simple task. im a machinest and have access to whatever metal i need. i will do the exhaust restriction tomorrow after work.
im also going to get me a boost controller in the next few days. thanks

RTS3GEN

What did you pull out and lay down? Sounds like you disconnected the reference line to the wastegate. If the line coming out of the precontrol or wastegate is left to atmosphere it's not referencing the back side of the diaphragm and the wastegate diaphragm will just stay closed and thus all the exhaust goes thru the turbine meaning too much boost. You want the wastegate and precontrol to "bleed" off some exhaust gas and keep the boost where it is supposed to be. On auto's you should see 9 psi to 10psi max, possibly 11 with your mods. If you are getting 13 on an auto..... Not good, no fuel mods to compensate. When does boost come on? 2500 rpm or 4500 rpm ?
Art

12leavu

iTrader: (1)

i should have been a little more clear with that. i pulled out of my driveway and laid down the gas pedal. ( alabama talk i guess)

im guessing the boost comes on around 3000. my rpm gauge only works when it wants to. the only other thing thats done to the car that i know of besides exhaust is.........it looks like the guy ripped out the airbox and bought k&n airfilters to go on every hose and zip tied them all together. i never gave the car time to spool up the second turbo. it boosted to much when i took off. it happened so fast it was atleast 12psi and when i drove it again it will get to 10psi at just 3/4 throttle. i haven't floored again since the first run. ....
rynberg is correct. there is a 2.5 in convertor necked down and welded into this giant exhaust...............edit ...guy i bought it from said there was an upgraded fuel pump. i will call him to find out the details on that.


"Sounds like you disconnected the reference line to the wastegate" by saying reference line, do you mean vacuum line? i havnt disconnect any lines from anywhere.

dgeesaman

iTrader: (7)

He's not sure if it's a high flow converter or maybe a resonated midpipe. I wouldn't rule that out just yet.

dave

rynberg

Good point.