PLEASE HELP....
I know I know... use the search button... But I've used the search button and it makes me want to spike my phone and computer....
So here's my problem...
I am modded with a 2.8 pulley and 60# injectors.... And a Slew of other mods.
My friend was in town and wanted to compare his Focus ST to my full bolt on SS LSJ.

Well all was well until the third run... Third gear at peak boost (18psi) there was a shudder/studder and a major loss of power. IAT2 s were through the roof. I let off and let everything cool down... The car runs fine MINUS the fact that it boosts far too quickly and doesn't pull. I never hit over 18PSI and now I spike WELL OVER 20psi and the power is just not there. My car pulled hard and best my friends stock STI... So I know what it should feel like...

Basically what I'm saying here is my car is making and maxing boost far too quickly and the lbs of boost do not match the power being made.

I also did some research and found that the PCM does not allow these cars to make boost in reverse... Well now all of a sudden my car makes boos in reverse but it drives as if it wasnt hitting boost...

So could this be bad timing?
Failed lifter?
Valvetrain issue?
Or the faulty bypass valve being stuck closed and causing boost to recirc and spike higher than normal?


Reminder THE CAR HAS A LOSS OF POWER BUT NO CEL.
It does not say ENGINE POWER REDUCED like I have read in many other threads... It starts and runs fine... As if it wasnt supercharged at all

 

still got a catalytic converter in it? if so i bet its plugged.

 

Its basically new.. Its been on just a few months. It is the ZZP mid length header DP combo. I can't imagine it being plugged causing 20psi+ spike/peak and allowing the car to build boost in reverse... But I will keep that in mind.
I am thinking it is the bypass valve... Not opening which is causing boost to recirc and spike higher than 20psi.. But I am honestly here to hear what anyone else thinks. Thanks for the reply.

 

its nothing to do with the bypass valve. the bypass valve doesnt limit boost, its used to allow air to bypass the blower when under vacuum to help with economy and efficiency. back in the day it was common to unhook the bypass valve cause people thought it added boost, thats been proven wrong and why you dont read about the boost bypass mod anymore. on the subject of it limiting boost, its not as simple as "no boost in reverse" type thing. the pcm varries the duty cycle on the control solenoid to limit boost, but its all based off the stock pulley, with a smaller pulley it may build some boost in reverse. same with the first gear boost limit. also all that can get thrown out the window with your tune as if torque managment was disabled you can see full boost at any time.

a valvetrain problem could in theory cause it (ive seen in race applications were you break a rocker arm the boost will increase) however the car would re running on 3 cylinders. however most of the time when we see a high boost/no power situation its caused by restricted exhaust. an easy test would be to remove the downpipe and take it for a drive, see if its better. yes it will be loud and obnoxious, however a quick spin around the block will be enough to tell you if its the problem or not.

a clogged cat isnt caused by the cat itself, its caused by the cat overheating. generally thats caused by a very rich condition, however retarded ignition timing can also cause it. lsj's are known for eating cats, thats why so many people end up going catless.

 

Damn... So I may as well swap to a 3inch catless afterall...
Thanks again. I'll look into the cat... And only way to fix is replacing it... Only other option would be to punch it out.

 

I would also suspect catalytic converter. If your tune is on the rich side it could very possibly have clogged the cat.

 

My cat has only been on for 6 months... Would you still suspect it?

 

If the the tune is rich enough and you have done enough pulls and stayed in power enrichment mode long enough then I believe so. My car is completely stock with stock factory cat yet it's rich enough that whenever I do a pull I can rub black soot off the rear bumper where the exhaust exits. So yeah anything is possible really. If it were me I would pull it off and shine a light through it to see if I could see through. If not then you'll know it's clogged.

 

the bypass solenoid along with the actuator on the blower limits or dumps boost it just depends on what the pcm is seeing

as for the valve train causing it yes i had one lash adj take dump it caused the boost to go over 20lbs

lsj are known for eating the original cats that came on them but its not often you see one eat an aftermarket highflow cat

check the valve train do a compression on al 4 cylinders could be you have a collapsed lash adjuster or more

 

Would the car still run perfectly fine with a collapsed lash adjuster? I mean the thing drives as if its NA.

 

mine did

 

Ok..so when I do a compression test... How will I know its a lash adjuster?

 

so CAT was clogged... so after tsking care of that problem now im only hitting 12 PSI. any ideas why? before the problem occured i was hitting 18psi. this is on a 2.8 pulley.

 

First question is, has the power returned? If it has then in that case your probably making more power than before because less back pressure in exhaust means more airflow through engine. Been proven that a full free flowing exhaust can reduce effective boost pressure by quite a bit. But just because I would unhook battery to reset computer just to be sure.

 

power has definitely returned... may have to see if I can get ZZP to tweak it a bit more or start learning some tuning myself.... peak boost is around 15-16 now so I'm think im all good.

thanks again guys

now to get some pics and a real sig...