I picked up my used 2K3 TB Evo yesterday, and after and extensive drive today, I've noticed I have a few issues with my engine. I can essentially put this all on the BOV that's on the car, an HKS SSQV. While driving, especially when going from 5th to nuetral when coasting, the engine completely dies...not the greatest feeling to lose power steering while at 50 mph . I noticed when the engine was pretty warm after some boost runs, the idle would dip down at almost 400 rpm and jump up again.
If it makes nay difference, the car also has a BnB turboback and a AEM Short Ram. So is it my damn BOV or something else?

 

replace it with a cheap stock diverter valve and see if the issue still permits. i have one i can sell really cheap if u want, just let me know

 

well mine dies sometimes to when coasting in 5th gear at idle or when just slowing down on the break in nuetral. these cars work on a lot of vacuum lines so you could have a problem there somewhere is my only guess.

 

Is this BOV VTA?

 

I figured that may be the other issue...maybe I have a leak somewhere? I'm getting a JDM MR Diverter valve for 90 bucks a friend local here so we'll see what happens after that. Thanks for the replies.

 

Yes, the SSQV is VTA...hence why I'm more than positive that's my issue.

 

Or the intake... do you have a flash?

 

Oh most definitely that will cause problems.

However, before you go off and buy a new BOV I do know they have recirculating kits for that BOV. My gf has one in her Mazda and had to get the kit -- you may want to check that out before forking out another 100 bucks.

She had the same issue you did -- would be going down the interstate and the car would die. Soon as we put it to recirculate the problem went away.

You could also check the MAF sensor and make sure it's not dirty.

 

dont rule out a poor idle air controller... it happened to me. i had to drive around always giving the car a little gas for 2 weeks before we figured it out and replaced it.

 

How's that easilty troubleshot down to the root cause?

Otherwise, borrow a stock BOV and test.
Put stock intake back on and test.
Ensure you don't have a nasty vacuum leak (boost leak test ,essentially).
Adjust idle screw.
Get tuned.

 

Maybe try switching back to the stock box. My car was stalling once a day when I had the HKS RS intake. As soon as I changed it back to the stock box, it stopped stalling.

 

Another person buying a used, modded Evo that has dumb ricer mods on it. People need to wisen up before buying this crap. Hopefully, this is the only problem, and you don't also deal with the guy removing an MBC and installing the wrong boost lines, the clutch won't start slipping in 2 weeks, the tires won't have to be replaced in 500 miles, and the brakes won't start shimmying when braking hard. Don't be surprised if most of these surface very soon after buying a modded 03.

Good idea on trying a JDM MR DV, but don't pay $90 for a used one, especially if that's your friend. They cost $105 new. Also, either remove that intake or get flashed immediately. That will also cause problems. The TBE is nice, but you probably need to find out if it has a fuel pump upgrade and a boost control upgrade. I would be surprised if the previous owner didn't have an MBC or EBC then put it back to stock...

 

Yeah also check the wires to the fuel pump, if there is an aftermarket fuel pump and it wasnt installed correctly it could be cutting the fuel to the engine. If the BOV doesnt come out to be the problem. I know cause it happened to me when i got my evo.

 

Its the blow off valve for sure.

 

Basically first recommendation to buying a Used Evo...

Either you or a friend, who knows a lot about Evos, RETURN IT TO STOCK.

Drive it for a couple weeks.

Then add mods back on that you like, PROPERLY.

I VERY rarely see modded Evos with mods like this, installed properly.