Sudden loss of boost and power..

[1999GSX_for_life]

Hey guys, I looked through some threads, and I couldn't find exactly what I was looking for. I just bought a Lancer Evolution VIII today. Has an Evo9 bov, Perrin intake, full 3" turbo back exhaust, custom lower piping for the inter cooler, and I believe some other custom piping. It has a gauge pod and I was driving from SLC to North Ogden, UT, (about 50 miles) and I needed to get ahead of some people, so I sped up and wanted to have some fun with my new toy. I hit 100mph and then slowed down to the limit, which was 80. No problems. Proud of my purchase. Running stock boost at 14lb-psi. After about 7-8 more miles, I noticed the boost level topped out at 9psi and the car didn't feel quite as zippy. Stopped at autozone on the way home just to see if any of those guys knew what was up with it. As I suspected, they knew basically nothing about any sort of street build and the guy told me I was running too much boost pressure through my turbo and that I need to turn it down to about 7. He said I probably blew it running 14psi. The car has 77k miles on it, so I guess it's possible I could have blown the turbo, but I don't think it would have just from going 100. When I'm opening the throttle, it holds the 9psi really well and I can feel it kick in, just not as hard as when I bought the car. Please let me know what you guys think so I can try to get the issue taken care of. Thanks much!

 

[Dsmkauai]

Boost leak test! Probably blew a coupler loose and created a leak. And it's not a honduh, these cars like boost .

 

[simplejoe]

That car can hold 14 psi easily. You definitely have a boost leak. Make yourself a boost leak tester. If you don't know how, just do a search on the site. I made mine for about $17.

 

[PlanZero]

I think it's hilarious that autozones sign says "advice" when 90% of the time that's the last thing the employees should be giving.
If you dropped 5psi after you romped on it you should be able to find the leak by just checking couplers and hoses. Most of the time you'll even hear a pop if you blow one off.

 

[miliman13]

Never ever ever lisen to any one who works at an auto..... Ect.. There's a reason why they work there and not a performance shop/ machine shop/ engineering firm. Ect.. Like everyone else said it can handle way more than (that dangerous number according to auto know it all's). Do a BLT.

 

[2gmitsueclipse]

Here are some resources if you have not completed or made a tester before:

Making the tool:

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

If your more of a visual learner:

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Using the tool:

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[1999GSX_for_life]

Thanks guys! I knew the car could handle it, and I knew the autozone guy was a dupe. I'll do a boost leak test and I'll see if I can find the problem. Thanks much!

 

[1999GSX_for_life]

Did a test around the block to see if it had cured itself, and it hadn't. Got in it to go get it registered, and she's boosting a very healthy 14lbs of pressure

 

[2gmitsueclipse]

I really hope you take the time to learn about your car, required maintenance, and basic troubleshooting. You may want to create an account here as it pertains to your specific platform:
http://www.evolutionm.net/

 

[1999GSX_for_life]

So the problem has come back. Same thing. Driving on the freeway, just cruising, no hard boosting, and my boost gauge is only reading 9-10psi, as before. Last time this occurred, it cured itself the next day. This time it's been three days and it's still not back up where it was, and this is the stock turbo and piping. I've read that it's supposed to push 19psi until around 6,000rpm, then drop to 16.5. Would it be safe to call this a boost leak? I don't know how to perform a boost leak test, but I know there's a million videos online about it. Also, when I got in my car this morning, my all electronic air/fuel gauge was not working, and my analog boost gauge had no light, but it's still giving a boost reading. If anyone can help me out, I'd greatly appreciate it!!

 

[2gmitsueclipse]

You can help yourself out by reading the posts in your thread, and trying them. If not, take it to a mechanic who can perform the tests for you. Making the tester, and using it were already posted in this very thread to assist you in troubleshooting your issue.

 

[chrysler kid]

If you own the car you should know more about it than the generic autozone employee. I try to avoid my employees giving out generic advice, no check engine light I'm sorry we can not tell you what is wrong with your car. 90% of the general population has no idea what an oxygen sensor is, or what a mass air flow sensor is. The best answer for them that we give out: your car will be fine but next time you take it in for an oil change you need to ask your mechanic to replace it because you won't pass inspection .

To be honest even if you came to my store and I specifically helped you and you asked why your car isn't making full boost and I told you to look at the couplers on the piping, and then you asked me to do it for you I would chuckle and point you to a mechanic. If I did it for you the next time you felt like your blow off valve wasn't as loud as it use to be you would come see me again and never try to learn about your own car

My advice is to find a good shop in your area to help you out or join the evo forums and go to a few meets to ask for advice if you are not able to learn more about the car by using the search feature available

 

[1999GSX_for_life]

checked all my couplers and clamps, no hoses or pipes disconnected, but I did happen to be lightly tugging on one of them to check for how much play there was and I could feel that the underside of it was slightly frayed on the woven hose, and this hose is on the output end of my intercooler. With that being the culprit of my leak, I've also been told that my wastegate could be leaking or that my blow off valve isn't recirculating. Both me WG and my BOV are off of an Evo9. The boost of 10psi at higher speeds (75+) is very loud and hissy almost and it accelerates slower at 10psi than it does at 1psi.

 

[1999GSX_for_life]

meant to say "with that being the possible culprit," and also, anything more than 4psi and the BOV blows perfectly, anything less doesn't recirculate it unless I'm putting a load on the engine, like accelerating at low RPMs in a higher gear and the turbo starts to spool and as soon as it hits 2-5psi, it's flutters like an HKS super sequential BOV. Just throwing that on the table as well.

 

[oneslowwdsm]

You're not doing anything by just feeling around for loose clamps. Excessive hissing means BOOST LEAK. You have to do a test, it really is not difficult. If you're not comfortable doing it, take it to the dealer or have a performance shop do it. Do not take it to just any mechanic, as most likely, they will make it worse. Good luck.

 

[1999GSX_for_life]

I know not to take it to just anyone, and I know it's a boost leak. I can make a leak tester but I need to find out why my gauges all just cut out. I just meant I was making sure all my hoses and piping were fitted snugly, not that that would fix the problem, because people were saying to do so. I'm just hoping I can get it all figured out soon. The nearest performance shop around is about an hour away so I'm just trying to figure it out before I take it all the way out there.

 

[1999GSX_for_life]

So I think I've found the problem. When I bought the Evo, the vented hood area is supposed to have that little shield under it, and mine doesn't. The guy I bought it from said he pulled it because he figured the engine bay got better air flow, and I could see where he was coming from, but I wanted to put it back in. I live in Utah, so it snows a bit. I believe my wastegate actuator rod that moves is getting stuck because snow has gotten on it, causing it to rust. I didn't have any proper lubricant for it, so I just wanted to see what a little WD-40 on the metal-on-metal would do, and sure enough, full 14.5psi and no loud hissing after. Only lasted a short while before getting stuck again. I heckled it and sure enough it was dry and my guess is the slightly rusted area is the culprit. I'm going to pull my wastegate and all its moving parts and polish it up lubricant it with something that will help keep rust away, and I'm putting the shield back in the hood vent. Hopefully that will fix it!