wacky boost pattern
 

ok,
so I have been getting some really wierd boost patterns as of late, and it doesnt seem very consistant. I usually see 5 psi easily, and it sort of bounces its way to 10. if I stay on it,. it will spike to 12 or more. I decided to do a vaccuum hose replacement this weekend, and picked up some silicon hose from the local parts place. I removed the uim and throttle body, and intake piping. I first noticed that almost none of my hoses were brittle or worn looking. (I have 75k on an original motor) I found 2 hoses that were shot, and I replaced a few of the easier to get hoses, but everything looked and felt really good in the rats nest. so I left most of it alone and replaced a few of the easy to get to hoses near the turbos. again, nothing was too brittle around there either, but I figured I might as well replace them. So as I am doing this, I noticed 2 things: first, most of the hoses in the rats nest did not have stock metal clamps, but the ones near the turbos did. and 2nd, I didnt see any "pills" in the hoses I did replace. so I am wondering if the hoses may have been replaced in the past. I put everything back together today, and took it for a ride. it now idles rough (which I am sure is my fault), and I didnt fix my boost problem. So I am hoping someone here has had similar problems, and can give me a head start, because I dont want to dissasemble everything if I dont have to.
thanks in advance,
john


engine is completely stock, and I have added a boost guage, and a temp gauge. I have also vented the bov to atmosphere. (please dont flame). No cel's either....

bumpity bump

ok, so I now have the uim, throttle body, and piping off again. so far, I still dont see anything up there that might be the cause. I did notice that I have 2 hoses that seem to have collapsed. I will post a picture of them as soon as I get a chance. I also noticed that the silicon hose I used feels very soft and pliable now. I am using a hose kit I picked up from autozone, and I am wondering if this is typical of silicon, or did I buy a low quality kit?

thanks

It's very possible the autozone hose is junk. There is a definitely such a thing as good silicone hose and cheap silicone hose.

There are only pills in 2 hoses, down on the turbos right off of the primary compressor and leading to the wastegate and precontrol solenoid. Not all cars even have them - some turbos have the restriction in the nipple there. Don't worry about the metal clamps, they were only in a few select spots.

Did you test your check valves? Have you removed your intake couplers to look for leaks?

I havent tested the check valves yet, but I did visually inspect the couplers. they seem to be in good condition. I think I may just order the rx-7.com hose kit. I should have know better than to use a 15 dollar silicon hose kit from autozone. what about the collapsed vaccuum hose? I havent had an oppertunity to take pics, but its almost completely flattened out. is this normal? or is this an indication of something else?

thanks for your reply