I just noticed today that my car is only boosting about 20 psi when it should be boosting 28. Here's the weird thing, it only does this about 70% of the time but the other 30% I'm actually getting my 28psi. I've checked all lines, piping, clamps but can't seem to find anything loose or linking. If I had a boost link, more then likely I wouldn't all of a sudden get my 28psi so I'm wondering if it may be my BOV (Greddy) which has been in the car for over 2 1/2 years. If not, where else should I be looking? I'm kind of lost at this point.

Thanks for any help!
Mike

 

what kind of boost controller?

 

does the car feel slower?

I pinched my boost feed line to my gauge one time...only showed 15 psi...car felt just as fast...maybe it's something simple

do a boost leak test either way

 

It's just a Buschur Racing manual boost controller. It's been on the car for about 1 1/2 years now..

 

It's definatly slower when it's only boosting 20psi. But the weird thing is that the car sometimes boost 28psi which is what it's suppose to do. I'd say now, every third try I get on the gas, I hit 28psi, and the other 2 times I only hit 20. It's hit or miss which is why I don't think it's a boost leak.

 

BUMP for more assistance please?

 

that is a little strange. you can check both the wastegate and BOV with a mity vac. to make sure they are not leaking and moving freely. have you logged it?

 

I plan on doing some logs this morning as it was just too late last night when I noticed the problem. This issue has got me stumped...

 

Check out my solution to my boost. problem. (copy) Finally, I managed to fix a major boost leak on my car. Before I was only hitting 13psi max and I kept hitting the fuel cut off. Couldn't figure out what was going on, so I talked to a few guys within our forum here. They gave a few good leads and ideas, so I decided to spend a little money before I would give up and sell the car. I spent close to $1,500 on new parts and another G for other mods. I bought a stock intercooler $100, stock header $100, Buschur intake $250, Buschur upper intercooler pipes $275, Buschur mini battery $225, HKS bov $225, 4ply couplers $75, T-bolt clamps $85, exhaust and turbo gaskets $75 and a few other things. After I assembled everything, I did a leakage test. I charged 25psi into the lower intercooler and heard leaks all over the place. With 25psi, my boost meter showed 5psi. FYI-T-bolt clamps need to be seriously tourqed down. After my 2nd test, 25psi charge and 23psi registered on my meter. Took the car for a test drive and I hit full boost with no problems.

 

Also, I used to have a Greddy type RS bov. When I did a boost leakage test, it would leak out of a tiny hole on the backside of the bov. The hole is built into the bov, but I couldn't figure out why it would leak. So I bought a new HKS from a vendor off evolutionm. This bov has no leaks. A leakage test shows all though and it's easy to make a kit. About $5 in parts.

 

2 &1/2 years is pretty good, I'll bet the inside of your Greddy looks just like this one.

 

Sure does. And you can see the little hole that I was referring to. I would was sure that my car had some major problem with it. I was going to replace the turbo and all this other expensive stuff. So many people told me to do a leakage test. So I finally did one and I was surprised from the results. I really didnt' even need to spend that $1,500 on my car. Just give a boost test a try before you waste too much money.

 

There's no way the valve will stay closed with the hole in the diaphragm. I always like to start with cheap fixes and work my way up, this one was pretty obvious as you could hear the boost being bypassed to the intake side of the turbo. My symptoms were identical to those of Nvr2old32 and it happened the day before I was getting a tune. Ended up getting the Forge RS and had to get rid of that because of drivabilty issues the Greddy works great till it breaks and is seams they all do.

Leaking out of that little hole is not really the issue and it's the leak from the top of the diaphragm to the bottom that's the problem.

 

Thanks for all the replies! Of course, I will start checking boost leaks but can anyone explain to me why about every 3rd try I get my desired boost level of 28psi? I mean, 8 psi different is huge. If there was a leak, wouldn't it be constant?

 

I'm definatly leaning towards there being something wrong with the BOV.