I am having a problem with my Evo. its an 03 evo - Stock. It first started as an intermittent problem. While driving, sometimes when accelerating the turbo would sound like it was boosting, but the car wouldnt get any boost. If I let off the gas then gave it gas again it would boost properly. I checked all my hoses, tightened everything, even replaced the vacuum lines with factory lines hoping maybe it was a small leak or something. No good. Eventually it has turned into a more frequent problem. If i'm driving around 50 lets say in 3rd gear not accelerating, but then try to accelerate, no boost.. i have to let all the way off, then punch it to get it to go. It is also starting to turn into if i drive the car for a long trip, the turbo feels like it stops boosting at all. is my turbo dead???

Also - I took the car in to get this fixed under warranty (car has 34600 miles) and am being denied coverage because I replaced the vacuum lines. Mind you I do have 2 Evo's and this one is the wifes, so its been left stock. The district rep says that there was 'playing around' near the turbo, so I could use any advice anyone can give on how to fix this. I do have an appeal open with the district Mitsu center for it, so we'll see what happens. Funny, but my lightly modded Evo has no problems...

 

What lines did you replace?

Sounds like a boost controller issue from what limited info you've given me.

 

Just the vacuum lines going from the turbo/wastegate to the stock boost solenoid. Its all stock on this car..no aftermarket boost controller etc.

And its the factory lines with the restrictor pills in them, so not a problem with that.

 

never heard of this problem. hmmmmmmmmm I cant help

 

If you're turbo was bad, I believe it would shoot out white smoke from the exhaust. Are you sure you didn't connect the lines wrong?

 

Sound silly, but you could pull the battery for 15 minutes. Let the ecu soft reset itself and see what happens?

 

Positive. The mitsu shop guys even looked at it to make sure at least the hoses and everything were connected ok. I mean, sometimes the car will boost just fine. Its really, really wierd.


Will give that a try and let you know results.

Any other suggestions would be greatly appreciated all!

 

i know a guy who had a similar problem. he was lightly modded and it turned out to be his HKS SSQ valve.

 

Did you replace the lines w/ factory lines w/ all the restrictors in place?

 

how much if any boost do you actually get? any check engin lights i just went thru this my self i had a bad cat that was preventing me to boost

try taken the two bolts that hold your down pipe on take it for a short trip see if u can boost ull know right away.

you can also take ur intake off see how much shaft play there is on the turbine it self just wiggle it gently if it moves or moves much it could be that

but b4 you go ripping the turbo off like i did check the exaust. easy 2 bolts hardest part is taken the stupid splash guard off

 

Thats weird, i sorta had the same problem, but it was my boost controller. I had a Turbosmart one, and in 3rd gear it wouldnt boost all the way, just to 14.5 and then next gear fine (or do the let off get back on deal). Im sorry to hear

 

Ok, I did the soft ECU reset, and no go. Yeah, I replaced the lines with factory lines (restrictor pills etc... took 2 weeks for them to order the dang part.) Still the same thing. Now the symptoms are like this:

Start it up and it runs fine. Warms up and boosts like normal. Drive it for a while and boost it a bunch or play hard on the boost and it just stops boosting. You know how on a stock evo when you start it up cold it doesnt let it boost until its warmed up some? That's what it feels like when the car gets heated up after driving in boost for a while. Also, the same thing with it not fully boosting, then having to let off the gas and give it some more gas are still there when it does boost normally. No CEL's or anything. Electronically the car must think everything is fine.

Part of me wanted to think that its the factory bov, but I dont understand why it would work fine til you hammer on it a bunch and get the engine all worked up then not work til you lay off for a while. Help!

*edit* something else I want to include in this, when the car stops boosting, if I drive it really conservatively or just let it sit for like 20 minutes running, it will eventually start boosting again. Wth?

 

Maybe something is heating up and getting loose? Just a thought since things seem to work cold, but not hot.

 

Anyone have any other ideas or suggestions?

 

Maybe you should check to see if the boost control solenoid is working correctly.

No boost means your wastegate or BOV is probably being stuck open. You can probably take the wastegate actuator off and move the flapper valve to see if anything is stuck.