Alright I bought my 03 evo used with 17k. Whoever had it before me had an ebc or mbc and the stock lines to the turbo and factory boost control solenoid weren't there, they were just plain autozone tubing. I put my boost gauge on and it only would boost 12psi max. I read on here sumwhere that the pills in the stock vaccum hose was what made it boost to 19.5 and taper off to 16. I figured that i would just say screw that and just buy an mbc and turn it up to a constant 19 myself but when I did that like the most boost I could push was 18psi. It held 19-20psi fine in first and second, but from third on the boost would peak and i would hit fuel cut around 5k rpms or so. I hear all these other people running 21psi till redline just fine w/o the flash or nething so I just want sum honest opinions and please dont tell me to search ive been doing that since 5am and only getting well maybe this maybe that. I also thought it would be the sparkplugs and the cold weather might have sumthin to do with it also maybe. I'm goin later on today to get the stock vaccum setup from mitsu and get new plugs (ne plug reccomendations) I figure I need new plugs nehow because im pushing 30k miles and I know that they haven been changed @LEAST since 17k so i figure i will try those 2 things first... Just please sum1 help me out with this because its killing me know what this car can do and what it is doing. I have a terribly slipping clutch and will have basically the whole car torn apart this coming weekend to replace the clutch/flywheel and add TBE and drop in K&N I am going to go through and thouroughly check all the IC pipe bolts and every vaccum connection on the car to make sure there is no leak. I also have an autometer pro comp boost gauge if that makes a difference.. don't c y it wouldn't work right but ima pressure test it just to be sure but im pretty sure its not the gauge. NE input here will be greatly appreciated!!!

 

nobody want to help??? :-(

 

I don't think your boost should peak at 19 psi in first and second gear. I think it peaks only at 3rd and 4th gear. In first and second I think it boost lower. You may have it set too high. I will do a search on this site for the boost readings in each gear - you should do the same

 

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chill man s ometimes it takes more then 5 min to get an answer. paragraphs are your friend.. i keep gettn lost about half way thru but thats what happens when you dont sleep in 3 days


im going to ask a few questions to help me understand what u are tryn to do

you have a boost guage correct?

are you trying to put it back to stock or you have a boost controler and what type?

if its mpc or even if its a ebc
turn it all the way down
and see what happens when u go full throtel you should get about 10 psi boost

when u turn it up slowly to get to about 19 20 psi

if you still get boost cut you may have a vacume leak some where possably where ur boost guage is taped in

or maby even ur mbc / ebc is hooked up incorrectly

hope this helps

hit me on aim maby i can help you out more

otnihc = aim

 

I have a MBC and when i turn it all the way down i only get like 15psi it will boost and hold 17-18, but I really just want to get it back to stock until i can get it flashed so i guess ima buy the stock vaccum lines with the pills in them since that has helped others with this problem. the whole vaccum setup for down there is only like $13 so whats there to lose, also when i rip everything apart this weekend i am gonna test every vaccum connection for leaks and replce the plugs. Nemore comments would be great keep them comin... also if ne1 has the stock vaccum lines with the pills and stuff that they would sell me that would be kool too!

 

Peazoo is correct.... you usually set a boost controler by doing pulls in 3rd gear to see where it peaks and what it drops too. If you have it set to hold 20 psi in first and second gear then it is no wonder you are getting fuel cut in 3rd gear... probably pushing 25+ psi there.

Keith

 

DOH! never looked at it that way just figured with the MBC it would boost the same PSI in every gear. so y would first be ne different than 3rd and 4th? and the gauge never shoots up to 25 it always cuts at 19psi on the nose.