Wondering maybe one of you have the solution to this?

After I got my car tuned I was boosting around 13PSI according to the boost gauge. It then dipped down to 10PSI after I sent the car to get some cam sensor checked. I thought it was then a slipping belt and I changed the belt - the car feels as if it running fine, but I still can't seem to get more than 10PSI.

I took off the intercooler and checked the tube that runs to the boost sensor and it seems fine as well. What do you think the problem could be?

 

Intercooler boots? Bypass Valve?

 

Only thing I can't/haven't checked is the bypass valve. How do I check that? The intercooler couplers are fine and is definitely not leaking anything.

I'm running a 17% SCP.

 

I changed my IC and al of a sudden couldnt get past 10 PSI untill 5000 RPM, so i'm replacing the bypass valve with the detroit tuned one to see if that fixes my problem...

 

Good luck! Let me know what the outcome is? I might go the same route then.

 

I'll let you know. I just ordered it last night so it may be next week some time.

 

I bought the bypass valve early on. I don't yet have a s/c pulley, however, I noticed a difference with just the valve right away. I hope it makes a difference for you all. For me, it was a great part for the money. It is a pain in the *** to put in. You have to remove the IC tube on the drivers side. But it didn't take too long.

 

Does it add any hp etc?

 

people need to understand this.............

UNLESS YOUR BPV IS BAD..........YOU WILL NOT GET ANY HP INCREASE

 

I've heard of people feeling a difference and claiming that the bpv is a good mod...but maybe its because theirs was not functioning properly.. thats what I'm thinking.

 

Thanks Jan, how will I know if my BPV is toast?

 

take it out and make sure it's shut completely, if not adjust it closed

if it is closed all the way, wire it shut and go take the car out for a quick spin and if the boost is now higher your BPV was bad

 

Will do! Thanks Jan

 

i changed my bpv just beacuse i thought i had a boost leak ,wich i didnt turns out there was something wrong with the 16% pulley now as far as hp i didnt gain anything but i did notice boost biuld a little easier with less throttle. for the price i dont think its a bad upgrade

 

Thanks for your input. What was wrong with the pulley exactly? I would to be able to identify if this the case with mine.

 

my car runs fine but it seems like i have some boost lag....doesnt really get going until about 3K rpm. bypass issue???

 

i think yes....
change it with a new bypass valve or with an aftermarket one...

i am positive you ll find your solution there..

 

worth a try for the price

 

New DT BPV ordered! Now the wait for it to get here ....

 

they where really quick with my order shouldnt take long and enjoy

 

Dito!

 

Ok I installed my bypass valve myself this afternoon. I can't say that I really feel THAT much of a difference. Perhaps I'm numb

How ever, my boost gauge is still reading similar PSI in boost. Perhaps 0.1-0.2 higher. Did I do something wrong?

 

The order of procedure in troubleshooting is to visit the last change in the system. Nothing should have been disturbed when testing the cam sensor, but inquire from the person who “checked the cam sensor” the steps he took to check it.

The most common failure of the BPV is a broken spring.


This is easy to determine, put a hand down the back of the intercooler output duct, actuate the BPV lever with a finger, if it moves easily, and/or makes a tink sound, it is a broken spring; a really bad one will not return to the original position. For a comparison, move the lever another MCS to feel for the amount of resistance is normal.

Another failure from a torn diaphragm or loose vacuum hose, will not allow the butterfly plate to open, and the first symptom is a decline in mileage.

I had one that exhibited an occasional 32k flat spot. I adjusted the butterfly plate, and because movement was a rough, checked the spring, which was fine although somewhat weak; reinstalled it but had no change in behavior. After replacing it with a newer version, which has lasted longer than any of the previous parts, problem solved, but much later I discovered the bad one only needed a drop of lube on the shaft end to free it up and operate smoothly.

If you can see light around an unadjusted BPV’s butterfly plate and blow into it from the top, you can strain your cheeks but very little air will pass, so complete occlusion does not offer a great advantage, replacing a faulty unit does. I manually adjust mine to a point of almost complete closure to avoid possible plate-to-bore binding later on.

I know you said you checked the intercooler bellows, but I’ve seen a clamp installed upside down and it appeared ok, even the bolts felt tight, however it was loosing more than a few psi.

 

An easy thing to check -- make sure the hose isn't slipping off the fuel pressure regulator. Mine had worked loose a bit and boost dropped from 18-19 psi max to less than 10. It also tended to spike and then drop rapidly as the fitting leaked under the pressure.

 

I'm going to take the intercooler off for the 20th time . I too think this is where the problem may be from. I'm actually thinking about replacing the entire transparent tubing that came with the boost gauge in case there are any holes that have been pierced by accident while installing certain parts at the workshop.