Rx-7$4$me

ok, so I finally got my damn downpipe on, and fixed the exhaust leak and boy does it pull hard!!!! only around 11 psi on spikes too! now. Secondary turbo time. I tried looking around, but I read other peoples posts and solutions and I just get confused, so can everyone that is able please help me? I get a perfect 10 psi till secondary where it slowley drops and ends up at around 4-5 psi at redline. if I let off the gas, and then mash it again it goes back up to 8psi then falls again. I checked the Y-pipe coupling, and one was cracked to crap, so I replaced it, no fix. checked for popped hoses etc, didnt see any. So what should I check now? please help. I want full power through the powerband

Stevo

bee

deff. sounds like a boost leak. Some cracks dont open until 10 psi has been present for several seconds, friend had simmilar problem, it was the top intercooler hose.
anyways im no expert so you should prob. check this out. It should help you narrow down the problem.

http://www.scuderiaciriani.com/rx7/boost_problems.html

Rx-7$4$me

bump

amp

iTrader: (50)

your going to need to completely check the entire vacuum system...this will include removing the UIM...

Rx-7$4$me

well, I pulled off the pressure tank and looked but I couldnt see anything popped off. Im gonna recheck my couplings and take off the UIM ... is it a bitch?

Stevo

jspecracer7

If it's never been taken off, it's a bitch.

My FD had the EXACT same problem. One of my intercooler piping couplers on the throttle body side had a crack in it at the bottom. Check that stuff first before pulling your UIM off

Rx-7$4$me

well, I replaced the pressure tank vacuum lines, and double checked my y-pipe coupling, no dice.What should I check next? oh , I looked pretty damn well under the UIM when the pressure tank was out, it looked pretty good, sept one thing which is in my other post.

StellarZ

you really need to take the UIM off and check the vaccum lines really well... how many miles are on the car? You are probably due for a silicone vaccum line replacement anyway.

Rx-7$4$me

71 xxx.. sigh... I really dont want to have to do that haha.. gotta pick up some vacuum line then

Rx-7$4$me

ok, I T'd into some lines tonight, heres what I found

Both pressure tank vacuum hose connections do

10 till 4500
5 when secondary comes on, then up to 8 instantly, and stayed till redline,

the one line on the pressure tank with the green valve thingy on it I t'ed in before the green thing, and got
10-dropped as secondary came online, then went up to 8 again.

tomorrow im checking the charge relief valve.

Also my CRV looks like its partially melted, and the lower vacuum line on it looks a lil messed up, so im guessing its this.

P'cola FD

All the things you talked about in your engine bat being melted makes me wonder if you had a small engine fire or some other strange occurance. It's not normal for things to melt.

Rx-7$4$me

well its the controll valve and the hose connected to it which is directly above the turbo manifold, its not melted to badly, just kinda charred like somthing really hot was touching it.

Bucrx7

Check your check valve and check both of your vacuum tank. The vacuum leak will cause your boost to drop, when you release your gas it builds vacuum then when you mash the gas it'll have full vacuum to use then it'll lose slowly loses pressure either through the faulty check valve or leaking vacuum tank.

Rx-7$4$me

anyone have a pic of the vacuum tank?

Stevo

P'cola FD

No picture, but it's the tank under your alternator, behind the idler pulley for the power steering.

Rx-7$4$me

do you have to rip off your alternator?

Rx-7$4$me

bump

StellarZ

It does require removing a couple things but is not that big of a deal... I cannot remember exactly what you have to remove off of the top of my head.