ok so i just completed my complete vac hose job, what a pain. my car is running much smoother and my primary turbo is boosting perfectly right at 10psi. the problem is the transition and the 2ndary psi it goes 10-5-5 down to 2 psi and when i release the gas i here a big whoosh sound, not the bov, maybe the charge relief.

My problem is very similar to this post on FD3s.net
http://fd3s.net/boost_problems.html

> I have been trying to diagnose the cause for my lack of boost above 4500rpm.
> I have gone through as many hoses as I can manage to find and everything
> looks good. The hose from the charge relief valve was very loose. I
> thought I had found my problem. The hose looked good and I put new clamps
> on it to keep it in place and figured everything would be fine. Upon
> testing, good primary boost (10 or 11), but once over 4500, boost drops to 2
> or 3 and there is a massive hissing sound. I know there is a leak
> somewhere, but I just can't seem to figure out which hose it is. This leak
> is in front of the passenger side and sounds like it is something big. I had
> almost everyone of those hoses from the intake and turbo off, but they all
> looked okay. HELP!!!!
>
> Another question, since this leak sounds so large. is it possible the large
> 2 peice hose on the intake can do that? The stock springclamps on it seem
> ok, but do these ever leak, or are they not under too much pressure?? I am
> asking because it just sound like sooooo much air is rushing through.
> Thanks for any advice.


I checked the lines and they all seem to be correct and they ar all brand new sillicon lines so i dont know what the problem could be. any suggestions? Greatly appreciated, thanx

 

about how long did it take you to do it?

 

about 12 hours of actual working time excluding breaks and sleep, i did it over a 2 day span.

 

alright cool. Im about to replace my turbos and rework all the hoses.

 

triple check all your vacuum hoses. i remember when I did my vacuum hoses I mixed up 2 hoses, charge relief and charge control . when that happen I was getting full primary then 1 or 2 psi of boost over 4500rpm. also did you replace the hoses with the restrictor pills in it?

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

 

i dont think this will help, but when i had this problem it was the pressure tank not hooked up right check the 2 hoses are around the right way maybe? and go the right place

 

thanx guys,

JP you sound like your problem is very similar to mine, ill check it out. about the pills i have 99 spec turbos that were replaced a few years ago by chuck at rotary extreme and i believe the 99 spec have the pill built in. also i bought a MBC but havent installed it cause i want the stock system to work properly

 

are you sure you connected all the hoses right?

 

im pretty sure, i took my time and tryed not to rush it.

 

Bump. When my car was running, I had the exact same problem after I replaced my hoses. My motor's blown now, so I never found out what the problem was.

 

I had a similar problem, I used some electronics cleaner and sprayed it into the solenoid (vac. port) and washed out all the built up carbon. I then hooked everything back up and it was fine.

 

which solenoid did you spry into? and whick is tha vacum side? thanx

 

Just clean out the sol. through the port. I sprayed it in the sec. turbo sol..

 

wow man that was helpful....

 

ok thanx ill give it a go

 

its been a while since I did a vac job but I remember that there are small bearing pieces that go within the hoses on the turbos. I had to remove it from the stock hoses and place them back into the silicone hoses facing the same direction. Could this be it? I'm thinking if it wasn't placed or facing the wrong direction it could be the cause of the problem.

Sorry for not being more helpful in terms and exact location of these pieces. I just remember they looked like little washers that allowed pressure to go one way only and it was placed within the hoses.

 

hey, use this diagram here https://www.rx7club.com/attachment.p...4&d=1203473021

This is the vacuum hose diagram for everything, fairly easy to understand. You will never have any questions about which hose goes where if you use this

 

thanx ive been useing that diagram.

it seems my pressure tank doenst make a woosh noise when i unplug the lines going to it, i dont know why tho, cause it was fine before i did the job.

 

bump

 

if the problem your having was similar to mine, I would really suggest you check all the hoses 1 by 1. sounds like the charge control valve isn't opening over 4500rpm. thats what happen to me cuz of the hoses i mixed up. if thats not your problem check if all the solenoids are plugged in properly and weren't mixed up (connectors). look if any of the wires were damaged while you were under there. I remember reading another thread that they were getting 1 or 2 psi over 4500 rpm because the turbo control valve wasn't opening because the clip fell of the turbo control actuator. good luck and keep us updated!!

i forgot to mention to check your check vavles too!! I changed all mine when I did my vacuum hose job

 

your right, but damn what a pain! i actualy replaced the ras nest with a newer lower mileage set. cause one of my old solenoids nipple was broken, any way i guess i have to tear into this again :/ Thnax for the help

 

your throttle cable or linkage could be sticking. do u have cruise control?