I am curious to know if anyone has had a similar problem: Recently my car hasnt making the boost it used to, the car is bone stock! So if I nailed it in 1st, the boost spikes to 1.35 ish then falls down to 1.10 - 1.0 bar in all the remaining gears?! When I bought it, it made 1.35 bar & tapers down to 1.2 @ peak revs, in all gears.

So I take it into the dealer & they replaced the boost solenoid. Now the boost is sometimes like it's supposed to be & sometimes you can feel the car just nose over midway through 2nd gear & boost is at 1.0 bar! Unfortunely it was raining like cats & dogs when I picked up the car & I was in a unfamiliar area to run it through several gears. It seemed okay on the freeway, then again it did before I brought it in! When I got home it was dry & thats when I found that the problem wasnt fixed.

I have checked all hoses, clamps, boost control lines. Everything looks ok, besides I dont hear any boost leak. The turbo just is not generating the boost. After the work, the turbo is capable of making the boost, but something isnt allowing it to be consistant.

The service manager wants me to leave the car there until it's fixed. They didnt properly diaganos the issue when I brought it in to be fixed & I am not that confident that they have a clue, other than throwing parts at it while thrashing away @ my ride.

Any other suggestions?

I told them to inspect the BOV & they said it was ok?

 

Try tightening the pressure-side hose connection to the BOV (the side plumbed into the aluminum pipe going to the manifold). I mean really tighten that thing. Mine would occasionally lose boost at WOT, and tightening that seemed to do the trick. I did it after reading that Shiv at Vishnu had seen the issue a few times.
Good luck with the monkeys at the dealership!

 

Thanks for the suggestion.

However, the clamp was plenty tight. Besides, the boost now goes away & comes back just as quickly within a gear. So the problem is more.........electrical/solenoid control, judging by the way boost is erratic. So I think at least.

Thanks again.

 

i had the same problem, and the TSB they have out for this says to replace the solenoid.. but the problem is in the solenoid lines, the line going to the intake constricts under full load, preventing full boost, try taking out the pill and see what happens.. if this doesnt work put it back in and bring it to the dealer, tell them to replace the boost solenoid lines.. the dealership i went to ended up replacing the lines with thicker more heavy duty with no pill, so now i boost about 23 lbs full load, all the time!

 

Looks like your dealer did a hack job, I'm sure removing the pill and replacing the hoses w/ non factory ones would not be authorized by mitsu. I hope it does not get very cold where you are or you will be hitting fuel cut all the time.

 

23 all the time??? Dude, that's not good...

 

hel_if_ino, you have 2 evos?

 

hey, dont tell me that, its a mitsu approved alteration.. before giving me the car back they had a long talk with the engineer that developed the fuel system to make sure the car could handle this, he said "oh sure". So im not worried about it. Hell, the tech was telling me while he was trouble shooting the problem, the help line had him remove the vacuum line to the solenoid allowing the car to boost with no limit, and he said he hit 28 psi!! i was like WTF! but its all on file, so if anything ever happens, its mitsu's fault.

 

well.. i only have one, but im taking credit for my dads evo.. since he also has one. He lives in minnesota, im in hawaii.. so i dont have two on hand..

 

28 PSI !!

 

Thanks for the info about the constricting line. Having them replace all the little boost lines would be a good idea since those lines are responsible for pressurizing the wastegate canister to hold the poppet valve shut.

However, a "constricting line" doesnt make any sense to me, because all the lines should be pressurized under WOT, especially between the solinoid & wastgate actuator.

Thanks again for the info. I'll suggest it the dealer.

 

I hope you got that in writing...

 

23psi all the time is NO GOOD! i dont care if the fuel system can handle it, the factory engine controls are set up to run 19-20 psi. Is the stock ECU going to compensate for this? yeah, timing will get knocked down some, but you really dont want to be pushing your car like this without a second opinion- A VALID ONE! I am sure DynoFlash, Vishnu, etc.. would advise against this. Just because your motor can handle this now does not mean that it will handle it when it has 50,000 miles on it.

I would take it back to the dealer and tell them to make it run STOCK boost. If they cannot fix the problem, tell them to give you a car that will run properly with factory parts/settings. Good luck, I hope to NOT see you posting pics of your pistons in a few months.

 

So how many people out there with faulty boost solenoids that were replaced by the dealer under warranty, had other components changed without being requested? i.e. boost related items.

 

actually, the vacuum line going from the solenoid to the intake boot is at a vacuum during WOT, the way the solenoid works is beyond me, i thought it was pretty simple and straight forward, but somehow it uses the vacuum from the boot to open the solenoid.. etc. not really sure on this so i dont wanna be wrong, but just to get my point across that not all the lines sense pressure.