Hi guys,

I have a very lightly modded 2003 Evo that was set-up by the guys at TurboTrix. All I have is a 3" Buschur turbo-back, a Buschur filter, and a Hallman MBC set to 20 psi. Mark at TurboTrix reflashed the ECU with a custom dyno tune and the car makes around 295-300 wheel hp. Like I said...pretty mild.

The car was returned to stock back in January (I considered trading it for an Evo 8 MR...but I changed my mind). I took the car to a local shop to get everything re-installed. Here's what happened:

The shop plumbed in the EBC the way they told me to at TurboTrix: turbo outlet nipple to bottom of controller, wastegate actuator to side of controller. Then the car went up on an AWD DynaPack.

On the first run, the car overboosted to about 25 psi. I don't know how they let that happen...but it happened. In the middle of the run, the car sort of stuttered for a second. Ever since then, we can't get the car to boost more then 12-13 psi no matter what we do!

What is the problem? Wastegate actuator? Boost solenoid? The wastegate itself? PLEASE HELP!!!

Emre

 

Just a thought: did you throw a SEL light? Try re-setting the ECU, My boost was all messed up last week, but it was a MBC not a EBC. also get heavy duty hose clamps and tighten every hose, check all vacume lines, I got a MR BOV and it seemed to help a lot. just some ideas. I hope you get it fixed soon. best of luck.

 

No, there was no SEL. Just to be sure, we went ahead and reset the ECU anyway (disconnected the battery and reconnected after maybe 5 minutes).


We checked all the vacuum lines and intercooler piping. Everything seems tight.


We removed the stock diverter valve and it seems to function normally (the diaphragm opens and closes). Do you think the boost spike damaged the DV? I thought they only opened under vacuum...so I figured it could not be the problem. Am I wrong?


Thanks for the advice! Right now I'm thinking that maybe something went wrong with the wastegate actuator (not closing fully or opening too soon) or maybe the boost solenoid.

Emre

 

boost solenoid is open so pressure is not being held back from actuator. The car is boosting on the actuator only (11-12 psi of boost). Something is wrong with the EBC.

 

wouldnt that also initiate fuel cut? or does flashing override that? anyway, an ecu reset (disconnect bat termonal for 10 mins) may do the trick.

 

It's just a Hallman MBC. Do you think the solenoid could be bad? Is it possible that the solenoid would open too soon?

Also, does anyone have a good source for these stock parts in case I need to change them? Is there an "upgrade" for the wastegate actuator or diverter valve...maybe from the MR or JDM evo or something?

Emre

 

I went to the JDM MR BOV it seems to be working better. As far as the wastegate actuator I have no idea I'm not even sure how the darn thing works.

 

quote The shop plumbed in the EBC the way they told me to at TurboTrix: turbo outlet nipple to bottom of controller, wastegate actuator to side of controller. Then the car went up on an AWD DynaPack.


Sounds to me like you have it plumbed incorrect. The factory ebc does not run off boost, its a bleeding valve. you need to "Y" both nipples "wastegate and turbo nipple" together to the firewall side of the ebc and the front end side of ebc has to be plumbed between the maf and turbo "intake"

 

heh, nevermind, just saw that you were reinstalling everything, thought you were putting back to stock

 

If the shop plumbed in the MBC incorrectly, could that cause my problem? What would make the car not boost past 12-13 psi?

Emre

 

Well, the guys at the shop called Turbonetics to help with some trouble-shooting. It sounds like the wastegate might be damaged

Does this sound plausible? Could a single overboosted dyno run damage the wategate like that?

Emre

 

When you say EBC in the first post what is it, stock or aftermarket?
Was the boost control put back to stock? I don't get a MBC to EBC change if you were going back to stock.
Were the stock hoses for boost control reistalled?

I can almost guarantee the wastegate is not damaged. I need more information and I will tell you the problem.

 

In the first post, I meant to say "MBC" (not "EBC")! We just re-installed my Hallman MBC. I wasn't going back to stock: I had gone back to stock in January. Now, we were putting my aftermarket parts back on the car.

Right, now the car's boost control is back to stock (all stock lines reconnected) and the car only makes 12-13 psi. Even when we put in the Hallman MBC, the car still makes only 12-13 psi...even if we set the Hallman to wide open.

It's pretty much as I described in the first post: they re-installed my Hallman, put the car on the dyno, and overboosted to maybe 25 psi or so. The car sort of "hiccupped" in the middle of the run...and has been stuck at 12-13 psi of boost ever since.

We re-set the ECU (unplugged the battery for 5 minutes...then again for 15 minutes) and it didn't help. We removed the DV and it seems to work (opens and closes). The wastegate actuator opens and closes at around 10-11 psi (when we tested with compressed air). Everything "looks" ok.

Emre

 

Well, we finally got to the bottom of the problem. It was the stock diverter valve. Even though it seemed to open and close properly, it was not holding boost. We installed a new diverter valve from Dahlback Racing:



Now everything seems like it's working fine. Thanks to everyone for their advice!

Emre