Hey all I am having a strange issue with my '04 MCS. Only mods are a 15% SC pulley and 2% crank pulley.

I am only seeing 8 lbs of boost unless I really beat on the car (multiple WOT pulls) and get it hot. I just started having this issue a couple days ago. Once I beat on it I will finally see 12 lbs from then on. But once the car sits over night and cools down its back to 8 lbs again.

Anyone ever have this issue? Almost seems like there is a boost leak that seals itself once it heats up.

 

Thinking to check the seals and intercooler boots would be the first place. Maybe cracking?

 

Well I did recently strip one of the IC clamps while tightening and I haven't bought a new one yet BUT in the meantime I was able to use a more aggressive bolt in it to get it to seal. It is definitely sealed and the boots are in excellent shape, no cracking at all. I cant be 100% certain that it's not that clamp but I really don't think that is the problem.

I also just recently reverted back from the DV mod because I didn't like the driveability of it. I was seeing a solid 12 psi when I had it hooked up but now that I reverted back to stock lines I am only seeing 8 psi. Again, I can't be 100% sure that it's related to my issue until I hook it back up and see what my boost is.

I could be jumping the gun without first properly fixing the IC clamp and testing the DV with the mod again. Maybe the modding of the DV weakened the spring and when I reverted back it is having a hard time holding? But why would it boost 12 psi after it's been beat on? So I'm not too sure about this theory.

 

Maybe your belt is slipping when cold but then gets grippy when hot? Are you using a shorter belt than stock for your 15% pulley?

 

Yeah, I'm using the correct sized belt and I am showing much more than a full hole on the tensioner.

 

You have an over all reduction of 17% you should be seeing 15lbs + I suspect a leak. To be honest though I would get rid of the 2% its bad news especially if its not a true damper ATI or Fluid. The solid ones eat oil pumps.

 

reset your ecu

 

Thanks for the reply. I'm actually replacing the 2% for a stock size because I'm getting bad pinging at only 12-13 psi, but thats a whole other issue (I think its due to our awesome 91octane here). I'm using a solid one unfortunately, the only reason I replaced it to begin with was because the stock one was making noise but I didn't have $400 to drop on a pulley.

Also, I just reverted back to the DV mod and although I haven't had much time to test it it does seem like I get full boost without having to beat on it as much. I'll test some more tomorrow.

 

I'll try this tomorrow. Thanks.