Loss of power

[em1toevo]

I have noticed that the car is falling on its face under full boost. When the pedal is to the floor, it will pull hard for a second and then lose power for a second or two-then finally regain full boost and pull hard to redline. What would cause such a hiccup in my powerband?

[BlewByYouEvoVIII]

boost leak

[em1toevo]

Damn...I guess I will have to track down the leak. How fast does boost taper after topping out? Mine tapers super quick-nevers stays at full boost.

[em1toevo]

Is there an easy way to go about looking for such a leak?

[BlewByYouEvoVIII]

Try taking it to a performance shop and having them do a boost leak test. They should be able to find the location of the leak. It usually is one of the hoses or your bov.

[em1toevo]

Thanks!

[mike.p]

bring it to us!!!!!!

[em1toevo]

I might have to do just that, Mike. I need to scape some cash together though. Christmas is breaking me, lol. How much do you think it would cost me?

[mike.p]

just for you ill do it for...um.......................................... ...................FREEEE!!!!!!

[TripperFx3]

just for you ill do it for...um.......................................... ...................FREEEE!!!!!!

Cant beat that! On an VIII if your running 21psi you should hit 21psi and than drop to no more than 18-19psi by redline. It should hold steady.

[mike.p]

yeah you should hold pretty close to what your spiking

[em1toevo]

Will I still hold boost close to peak with the plastic VIII bov? I thought it leaked a lot more than the metal IX bov. I did another pull tonight to see if I could narrow down exactly what was going on. At around 4k RPM it just sort of pauses for a second(losing boost), and then it just picks right back up again.

[BlewByYouEvoVIII]

The plastic one should even hold 21 psi, the MR metal one is supposed to hold 24 I believe. Let me know when you take it to Mike. I may go with you. I promised him I would stop by ;)

[em1toevo]

I will definitely let you know when I go Ryan. It will be soon-I can tell you that.

[mike.p]

yeah the 9 bov are good till 24.....but honestly it kinda sounds like the clutch sliping??? cause if i havnt read it wrong your saying under wot you pull hard till 4k the it pauses then picks back up...correct?? also at around 4k does it seem to rev kinda quik/high then fall back down a little bit?? not trying to scare you..lol when you say loosing boost.. what does the boost fall to?? cause if i remeber correctly your still on stock clutch right?? also how many miles do you have?

[em1toevo]

27k miles so far. I really don't think it's the clutch slipping cause it is pulling for a little bit into boost before the sudden drop off.

[em1toevo]

It doesn't rev up at all during the pause either. It's like I just backed off the throttle for a second and then stomped it again.

[em1toevo]

Btw, the 4k RPM range, where it pauses, is a close approximation.

[em1toevo]

I just found this link to make an I/C pipe tester. I might try to do that as well. Seems easy enough.

http://vfaq.com/mods/ICtester.html

[TripperFx3]

I just found this link to make an I/C pipe tester. I might try to do that as well. Seems easy enough.

http://vfaq.com/mods/ICtester.html

Its easy to make it, but you need pressuized air and i believe you have to rotate the engine to TDC

[alg626]

After it pauses does it go back to full boost or never climbs that high, or are you letting off the trottle after the lose or power

[em1toevo]

Right after the pause it resumes to redline as if nothing ever happened. The strangest part is that it doesn't do it every time.

[em1toevo]

How do you rotate the engine to TDC? Do you have to take the cam gear cover off? That seems like a pain.

[alg626]

Right after the pause it resumes to redline as if nothing ever happened. The strangest part is that it doesn't do it every time.


I meant the boost does it go to full boost after the pasue or not all the way

[em1toevo]

Its kinda like this:

Hit the gas WOT(usually in 2nd or 3rd gear)

Just as I spool up-pause(like I momentarily backed off on the gas)

After a quick pause(pedal still fully depressed), it resumes to redline with all the pull it should

[em1toevo]

I'm going to take a drive in about an hour or so and try to figure out more details. I haven't been doing as many WOT pulls as I have recently, but I have noticed it before and schrugged it off.

[alg626]

Well it sounds like it could be your BOV, mine would stay open afterwards and i couldn't hit full boost only like 15psi, i could also hear it. Seems like right at full boost it opens then closes, Just check the vaccum line from the top of the bov, to make sure its all the way on or no cracks in the hose, i don't think that would be the problem becasuse if there was a leak in that the car would idle like crap

But also could be a leak somewhere in the flex pipe of the IC pipping

[em1toevo]

It idles like a caddilac. But I do need to check out the flex hoses.

[mike.p]

yeah you need to do a boost leak...but to put it top dead there are markes on the block you line up...you dont need to mess with the cam gears

[em1toevo]

I won't mess with the cam gears. With the windows down, I have been noticing that it almost sounds like its backfiring(running too rich I guess). After inspecting the lines and thinking about it-I can't come up with any other conclusion.

[mike.p]

just bring it up here to us and well see what we cant find...its hard to diagnose what exactly is wrong with it over the net...lol

[em1toevo]

^^definitely