Utah Evos
Evolving Member
Joined: Mar 2007
Posts: 316
Likes: 0
From: Ogden, Utah
If it is leaking boost, then the maf is seeing extra air, and delivering fuel for it, but the air never makes it to the cylinder, thus making it too rich, choking, etc.
You may have to push through it to see if either it blows off a hose, or that the bov is actually leaking. replacing that greddy unit with stock is a good measure just as a matter of course.
You may have to push through it to see if either it blows off a hose, or that the bov is actually leaking. replacing that greddy unit with stock is a good measure just as a matter of course.
I have seen a few posts of people having a spiking problem with the Forge UNOS but I've found nothing like this. Thanks again for the help.
Hey thanks alot for your help I really appreciate it. I put the stock bov on and it made no improvement. Then I disconnected my MBC (Forge UNOS) and hooked up the stock solenoid unit and that was where I got the most improvement, except I'm only getting about 13-14 lbs boost. 15 and above is where I was having the problem. I have a Hallman MBC I will hook up to see if that brings the issue back with a little higher boost, or if for some reason it was the Forge causing the problem???
I have seen a few posts of people having a spiking problem with the Forge UNOS but I've found nothing like this. Thanks again for the help.
I have seen a few posts of people having a spiking problem with the Forge UNOS but I've found nothing like this. Thanks again for the help.
Hey thanks alot for your help I really appreciate it. I put the stock bov on and it made no improvement. Then I disconnected my MBC (Forge UNOS) and hooked up the stock solenoid unit and that was where I got the most improvement, except I'm only getting about 13-14 lbs boost. 15 and above is where I was having the problem. I have a Hallman MBC I will hook up to see if that brings the issue back with a little higher boost, or if for some reason it was the Forge causing the problem???
I have seen a few posts of people having a spiking problem with the Forge UNOS but I've found nothing like this. Thanks again for the help.
I have seen a few posts of people having a spiking problem with the Forge UNOS but I've found nothing like this. Thanks again for the help.
Tracking a boost leak can be a pita, but you can start by taking apart every connection, cleaning the mating surfaces with brake parts cleaner (outside of the hardpipes and inside of the soft hoses), then put them all back on. The stock hoses are okay, but expand and are made of rubber, so one could be bad. You may want to consider the samco hose kit (i think rallysport carries them), and some t-bolt clamps from napa (there is a part list of the proper clamps in the engine section i believe).
LOL
Evolving Member
Joined: Mar 2007
Posts: 316
Likes: 0
From: Ogden, Utah
It may not be the boost controller, but a leak that makes itself known at higher boost levels. That's what i would suspect the most. Do you have all stock soft hoses? stock clamps?
Tracking a boost leak can be a pita, but you can start by taking apart every connection, cleaning the mating surfaces with brake parts cleaner (outside of the hardpipes and inside of the soft hoses), then put them all back on. The stock hoses are okay, but expand and are made of rubber, so one could be bad. You may want to consider the samco hose kit (i think rallysport carries them), and some t-bolt clamps from napa (there is a part list of the proper clamps in the engine section i believe).
Tracking a boost leak can be a pita, but you can start by taking apart every connection, cleaning the mating surfaces with brake parts cleaner (outside of the hardpipes and inside of the soft hoses), then put them all back on. The stock hoses are okay, but expand and are made of rubber, so one could be bad. You may want to consider the samco hose kit (i think rallysport carries them), and some t-bolt clamps from napa (there is a part list of the proper clamps in the engine section i believe).
I found this link on another thread to do a pressure test on the system.
http://vfaq.com/mods/ICtester.html
I'll let you know how it works and what I find. I also changed my plugs to a cooler plug and checked my cables and coils, it smoothed it out a little but that's still at 14 lbs boost, but like you said, it might be a boost leak that only shows itself at high boost.
Newbie
Joined: Jul 2005
Posts: 16
Likes: 0
From: SLC Utah
Here is a few fast pics off my phone. Will try to get some better ones up soon.
You can see part of the Evo IV next to it if you look really hard.
Here you can really see what the finish looks like. I think it turned out pritty good
Some pics of that nice RICER WING
You can see part of the Evo IV next to it if you look really hard.
Here you can really see what the finish looks like. I think it turned out pritty good
Some pics of that nice RICER WING
But honestly, is the wing a joke?
I like the wing
I want one for my car now
I think all the car really needs is some 18x9 wheels one this street setup or some 15x5 and a Rally suspension setup like the subaru WRC car 
I want one for my car now I think all the car really needs is some 18x9 wheels one this street setup or some 15x5 and a Rally suspension setup like the subaru WRC car
Newbie
Joined: Jan 2008
Posts: 13
Likes: 0
From: SLC, Utah
hey i just got my evo a few weeks ago and i was looking at the boost gauge in it and at idle it reads negative boost,
is that how it should be or is it suppose to be at zero? it is a defi d-gauge. any one know anything
is that how it should be or is it suppose to be at zero? it is a defi d-gauge. any one know anything
Newbie
Joined: Dec 2006
Posts: 13
Likes: 0
From: utah
if its a vacuum and boost gauge it will read vacuum till your in boost so yes its working correct
Evolving Member
Joined: Mar 2007
Posts: 316
Likes: 0
From: Ogden, Utah
It may not be the boost controller, but a leak that makes itself known at higher boost levels. That's what i would suspect the most. Do you have all stock soft hoses? stock clamps?
Tracking a boost leak can be a pita, but you can start by taking apart every connection, cleaning the mating surfaces with brake parts cleaner (outside of the hardpipes and inside of the soft hoses), then put them all back on. The stock hoses are okay, but expand and are made of rubber, so one could be bad. You may want to consider the samco hose kit (i think rallysport carries them), and some t-bolt clamps from napa (there is a part list of the proper clamps in the engine section i believe).
Tracking a boost leak can be a pita, but you can start by taking apart every connection, cleaning the mating surfaces with brake parts cleaner (outside of the hardpipes and inside of the soft hoses), then put them all back on. The stock hoses are okay, but expand and are made of rubber, so one could be bad. You may want to consider the samco hose kit (i think rallysport carries them), and some t-bolt clamps from napa (there is a part list of the proper clamps in the engine section i believe).
I think I figured out it was the spark plugs, way too hot
, and a moron (me) had the gap all screwed up. We did a boost check and it held pressure just fine. I put my Iridium plugs back in, along with my bov and mbc, and turned the boost up to 19 and it did a pretty smooth 3rd gear pull from 2000 to 5800, at which we encountered some knock. GEAR HEAD did some datalogging for me and it looks like a proper tune will probably fix that problem. Thanks for the help GEAR HEAD and EFICK.