So ur saying its not the factory boost control solenoid but the hks ebc boost solenoid correct?

 

yeah, since your factory one probably isn't doing much right now except sitting off to the side plugged in to prevent the cel from coming on right?

 

Had a similar problem today. Low boost and late at that too.
Turned out to be an exhaust leak..
I would check your exhaust studs, header joints and things like that. Maybe s/th came loose?

 

This is very probable and something that I think may be the issue on mine. I recently Seafoamed (don't want to hear it) my Evo and sucked into the intake manifold using the brake booster line. While plenty of smoke came out the exhaust at the rear of the car, a few puffs/tendrils of smoke came out from underneath the exhaust manifold heatshield. I suspect this may be my issue and very well could be your's as well since we have similar symptoms.

 

I will check out my manifold and stuff for any leaks tomorrow when its daylight after I get off work. Im working to much right now to get a chance to check anything out Thursday its having its driveline fluids changed so when its on the lift I will look for obvious stuff such as vacuum lines, and report back thanks guys ill let u know how it goes asap for anyone else with this problem

 

One thing im not getting when people say is the boost solenoid is how could it be a bad solenoid (hks evc solenoid) when the boost controller is not on? If its off isn't the solenoid off and shouldn't it boost to factory?

 

Without the boost pill and the factory soloniod running the wastegate and your ebc turned off you are only going to run wastegate pressure.

 

So if my ebc has always been turned off yet I was at 19 psi but now only 14 I should check the stock solenoid correct? I found a thread about testing one. It said to use a test light and ground it then put power to it and listen for it to click. It also said if the click was not loud enough to hear u can try to blow through the solenoid nipple if u can't and it has power its bad. Im going to try this on both solenoids tuesday or Wednesday after work

 

At least its not like my car. My car is over boosting bad. I just installed a Invidia catted dp and Invidia N1. I gave it some gas and my car shot up to 25 PSI's which I know is way too much. I know the previous owner had a HKS actuator with a tune so I suspect that maybe the factory actuator could be damaged. Thats what I get for buying a used car with parts. Hope you get your problem figured out!

 

best way to fix this issue is bring it to a reputable evo shop, have them diagnose it and then get a tune at the same time.

 

Lol easier said than done my friend. The closest shops that do mess with aftermarket stuff is 70 miles away and when they turboed my honda they blew it up by using teflon tape on the oil return I think the turbo lasted maybe 3k miles and was. Never really beaten on. The next closest shop is in knoxville three hours away. Middle tn blows hard. Plus I know its prob something small im just overlooking and they will try to charge way too much.

 

I would if you could. Check the j pipe. Mine was bent. blew the gasket. and was causing me a leak

 

Pull the battery. Step on the brake and reset the ECu. If you had a substantial amount of 'noise' your knock sensor may have turned your car into a dog.

I had the exact same issue 3 weeks ago, my downpipe was clanging on the xfer case. I took it back to the tuner who installed a muffler downstream of the dp and he couldnt find the issue BUT it didnt come back after the he adjusted it away from rattling. Now he could be BS'ing me and he also re-tuned the car for 2 more PSI. However the car before the muffler and after the retune...would slam the gage. during the bad period it was perky to 4K with maybe 10PSI or so and then would just creep up on boost until it hit 18 at well north of 5K in third gear. Dog Slow, flat no acceleration. I had no leaks. Other than a hallman/tb/intake/tune my car has nothing tricky.

If you reset the ECU and then 'teach it by brake boosting' for a bit. see if that doesnt make a difference. If it doesnt I will keep lurking because I can't believe a knock sensor would flatten the car out so bad....

 

^what do u mean when u say teach it by brake boosting? Do u mean go down the road and brake boost a couple times to see if it goes to 19 again?

 

I am not sure if this applies to evo's. But Shiv at Vishnu used to tell the subi's to do it.

Here's a reference link the real deal is prolly out on the net someplace:

http://forums.nasioc.com/forums/showthread.php?t=302047