Driving yesterday and went wide open throttle and everything was fine (nice strong boost 12psi). 2 minutes later went wide open throttle again to merge onto the highway but noticed I had no power. Took a look at the boost and sure enough it was not even hitting 5psi. Every gear and ever RPM when I floor it, it will only hit 3.5 to 4 psi. I checked the transition in second gear and it looked to be 4-2-4. I can feel it pull harder after 4500RPM when the secondary hits but boost still won’t pass 4psi.

So I took all the pipes and couplers off and examined them and they were all fine (even removed the intercooler). No tears in any of them. Tightened all clamps and did a thorough visual to make sure no vacuum lines popped off (did not find anything). Took my time to check all tubes short of removing the UIM to see the rats nest but all those have been tie rapped so the last thing I want to do is remove the UIM to look under there. Went for another test drive and no change.

So I figure maybe the cat is clogged. Took out the midpipe (I have a catless downpipe) and took it for a test drive and no change.

Floored the car in neutral to see what boost it would hit in the upper RPM and all I get is 1.5psi rather than the 4psi it should get.

The next thing I was going to check is the Double Throttle body. Is there a method to see if this is working correctly?

I was also thinking maybe a check valve went but I have no idea how to test those or which ones to test (where to start).

Do you guys have any suggestions? I read the troubleshooting for sequential systems but it alwyas leads to boost leaks and I do not seem to have one.

Any help would be greatly appreciated.

Thanks, J

 

yea me too im haveing the same prob, i checked all my lines but still nothing

 

Well after reading thread after thread with people who have had the same issues as I am having 98% of them seemed to be a busted hose or coupler. Even though I already took everything off and looked at them for cracks/slits decided to take off my lower intercooler pipe again because of one post in particular that I read. The post mentioned that it is some times hard to see if the hose has spilt even when squeezing it. I also remember a metal shield on the hose that I thought I would take off to look under. Well I took the pipe off and didn’t even need to remove the metal shield. I squeezed it in a bunch of places and sure enough there was one long slit that was hard to see unless you squeeze in that specific spot.

All that to say you may want to revisit the coupler/hose theory. Man I could have saved so much time had I knew the slits can be invisible. LOL

Good luck and hope you find the problem. I know how frustrating these kinds of thing could be.

 

To give you an idea of how hard it is to see.

No slit...



Slit (had to squeeze just the right spot to see it the first time)...

 

Normally when you get a boost pattern anything near X, X-2, X you just have a leak somewhere in the piping.

Anything wierd like 0 secondary boost.....to much boost....etc etc is a problem in the nest.

 

Cool, good to know. I actually suspected a leak to begin with but I checked everything and didn't see a tear in anything. I just didn;t lok hard enough plain and simple. I now know you have to squeeze all the pipes in basically every spot to reveal the split.