idle problem

okay so i got the DIY turbo kit on the 96 impreza 2.2 and wow! what a difference 7 psi can make. the only problem is that when i push the clutch in at anywhere above 1500rpm it goes into a low idle then kills. if i decelerate in gear down to 1000rpm and then push the clutch in the idle bounces between almost 0 and 1000rpm and then stabilizes at normal idle. any ideas as to what the problem is? maybe air/fuel ratio at idle?

 

Do you have a boost gauge? Do you have vaccum at idle? Might want to check for a leaky vaccum line.

 

mine does the same thing, have you let it warm up a bit? since once mine gets warm the problem stops. I am thinking mine could be spark plug issues.
and it could be due to the fact that the ecu has no clue whats going on anymore.

EDIT: what turbo are you running to get 7psi? or are you using a mbc? since my tdo4 gets me about 5psi

 

ueah even when its warm it does that. just when i push the clutch in though. and yeah a grimmseed mbc. works great

 

i'm comfortable at 5psi, my motor has alot of miles on it..
and have you upped your octane? you need at least 91, cuz my first tank was 87 and it ran like crap it even knocked at idle, filled up with 93 and she runs great.

I also don't know how you have your setup run, but did you run all the breather hoses back into the intake system? only the biggest one off the intake system HAS to be ran back into the system, all mine besides that one just dump into the engine bay.

Any CEL's?

and how does it idle? does it run rough (fluctuating idle)? if so you may have a vacuum leak someplace.

i had a few more question's but my blackberry wouldn't let me send them so i had to try and remember them thru work but low and behold i forgot..

i'm going to be poking around at my car, i'm leaning more towards checking the gap on the plugs since i think that's my problem..but if i find something out it may lead you in the right direction..

 

yeah im running 91 octane right now. ran the IAC and PCV back into the intake. yeah i tripped a cel but i believe its because the rear O2(emissions sensor) isnt plugged in. it fluctuates at idle back and forth a little less each time before settling on normal idle but if the rpm is over 2500 and i push in the clutch it fluctuates too low and kills. and yeah if you think of those others just ask more than open for a fellow DIY

 

when i first started running mine i got a few cel's, i don't remember them all off hand but one was for a map sensor, one was for the front O2(which i knew because it hardly ran at all), and a few for the auto trans that is no longer in the car.

and i really have to get this figured out, since last night i think you jynx'ed me since it was doing it more often than i liked. But with your's if you let it die, restart the car does it fix the problem? because if i let mine die it will fire right back up and wont do it again until i shut the car off again. I'm beginning to lean more towards an air/fuel thing. since other than it dying it runs perfect, boosts great.

I am curious in how well the ecu is taking the additional boost, since stock (before turbo) it reaches 0psi at WOT. Now i don't know if the ecu is trying to learn on the boost, then when there is no boost it still thinks there is and is adding to much fuel causing the car to die..I'm shooting in the dark since i am by no means a pro at turbo setup's.

I think my next try may be to pull the plugs again and check them to see if that gives me any signs of rich/lean. otherwise i may invest in some injectors out of a turbo'd legacy to see..but i have heard they can cause a really bad idle, and i have heard they can run great.

 

when it dies and i start it back up it idles normally but when i increase the throttle and let the clutch in again it will die. the addition of too much fuel by the ecu trying to compensate was what i was thinking. idk if maybe it is still adding fuel even after you let off the throttle because you are still in boost down to around 2000rpm(differs from different turbos) and then all the sudden there is NO boost and too much fuel causing it to stall. like you haha, just a shot in the dark. i got an SAFC coming next week so ill fidle around with the air/fuel at idle and see what that does

 

i hope i don't need to do anything to make it idle right, since mine was done on the dirt cheap and don't want to sink any more money into it.

but you shouldn't be in boost once you let off the throttle since the flapper should shut. Cuz if i let off the throttle it goes to -XX and if i "engine brake" the car pulls -30. Since as soon as i hold the clutch down i'm in the negatives already for boost pressure. I only build past 3 psi if i pull it WOT then it goes to about 5.

Now what i'm not sure of is if its too lean or rich, i haven't pulled my plugs to check it out. then again i may just live with it since it doesn't do it every single time i push the clutch in. but tomorrow i'm going to be poking around and seeing what i can find out.

 

Dos the car idle just fine on its own. ie if you start it and let it idle does it hold a constant RPM or does it fluctuate? My first guess would be a vacuum leak of some sort, and when you let of the throttle the engien doesnt "catch" itself before the RPMs drop to low. It could be an issue with fueling but I am not sure what it would be. When you let off the throttle you should read -xx for manifold pressure (no boost) which the MAF sensor is also reading and in combination with the TPS sensor will lower your injector output accordingly. So I doubt that the ECU still thinks you are in boost when you clutch in/let off.

Are you running the stock wieght flywheel/clutch? a lightwieght setup could have a similiar effect to what you are describing.

 

yes on startup and when i just let it idle it does not fluctuate, it idles normal and does not fluctuate. I am running stock clutch and flywheel

 

try this and see if it still persists, i can get around it fluttering the idle..when you know you're going to be slowing down, let off the throttle wait a second or two then depress the clutch. See if that helps any, since if i do it this way the idle won't fall til it kills.

oh and take dynapar seriously, this guy knows his stuff..since he has been through this before..

edit: and how's your gas mileage? mine has been not so good lately..wondering if there is a coincidence..

 

I tried that and it still died but i talked to 3rik and he said the placement of the iac inlet is crucial for this as he had the same problem. and yeah my mileage sucks but im gonna blame the driving ive been doing now that its got boost

 

3rik very well could be right about the AIC placement. I have not heard of this before but it does sound plausible since I know that hooking up the AIC wrong can cause the car not to idle.

I have never experienced this on either of the times I have run my DIY turbo setup. This very well could be that both times I ran the turbo setups I was using an automatic. Which does not really have an issue with catching any falling RPMs since it is always in gear.

 

okay now its making a little more sense. im gonna get a little more info from 3rik and mess with the IAC location to figure out if that will help.

 

hum, this sounds like something to look into. since my line for the IAC is almost 3 times as long (not sure if that makes any difference)..now how do you go about testing this without blowing holes all over the intake system? since i don't have any spare intake bits lying around anymore. and where is best for it? closer to the turbo or?

 

now that my friend is what has been tossing and turning in my head im going to talk to 3rik about it and when i figure something out ill let you know. This is my first diy kit so its all trail and error but with much help from 3rik(thanks 3rik) haha im only 16 so some of this is new

 

lol same here(except age, got 10 yrs on ya) and dynapar has been my saving grace..did you run a custom UP or use the wrx manifold/UP with crossmember?

i think tomorrow i might see if i can find some exhaust tubing i have lying around and bend up a custom, custom intake just so i can blow holes in it all over hell and see if i can make something work. i may also be able to steal some intake piping from the 5 some odd cars i have lying around in the woods..

i am just curious if the length of the tubing make a difference or if its the location based on the stock setup, because stock its only a few inches from the TB, but now its more than a foot, with almost 2 feet of tubing. last picture before the video is what i'm talking about, with the L gray fitting or the second picture IAC line

stupid vacuum systems...

 

i went the custom uppipe route because i got a cheap dp from my brother (justin @ grimmspeed). i like that custom intake idea. Let me know if you see a difference. I'm gonna do a little research and see what i can find. It looks like your IAC is a little bit farther from the turbo than mine. stupid vacuum systems is right...

 

installing my hood scoop took alot longer than i thought, so tomorrow i'm going to raid the cars i have and see what i come up with. otherwise i'm going to the auto parts store to see if i can find a radiator hose that works for me, i am assuming that a radiator hose should get me by, since it will be cheap and i can modify it til it works then figure out a "finished" product.