[RESOLVED] BOV cause over boosting?

[spicoli619]

so i have a HKS SSQV blow off valve on my 1996 talon TSI. (well was on my car)
when i had it on my car it was WAY over boosting like 20psi at 4k rpm. so i took it off and put the stock one back on. For 2 reasons, to see if it would fix the over boosting and i also had to smog my car. it passed smog and now its not over boosting at all.
im new to turbos and such and have searched the forums but with no luck. i am wondering why it was over boosting. it didnt have the Recirculation Kit on it so mabe that might be it. but im not sure.
how would i fix this problem? i do have a MBC that is going to be put on. but what im wondering is will that fix it? or will the Recirculation Kit fix the over boost problem?
please and thank you for all your advice.

 

[the_mork]

I wouldn't get worked up about it for a $10 part.

 

[rEclipserGST]

I wouldn't get worked up about it for a $10 part.

So i should just let a shop charge me $210 to "fix" my car, instead they break something and dont tell me. But since its an easy fix, i shouldn't get "worked up"? You sir, do not understand the concept of "good business" then.

 

[the_mork]

I don't mean to argue with you over "good business", I really am not sure what you even mean my by that but I can assure you that I know a share about business and keeping clients happy. I also know something about pricing.

What were they doing for your car when they broke your bov? Are you upset about the broken bov or the price of their service? Being punitive about replacing a part that the shop broke does not put money back into your pocket and is a fight that doesn't have a good ending for you. If you think that you were overcharged then I suggest you look into that directly. The part is ~$10 and I can assure you that they are not liable for damaging a part that they were legitimately working on as long as they were not significantly incompetent (they almost certainly were not).

I am merely offering advice here but I would suggest that you take the opportunity to upgrade your car's reliability and performance and in the future avoid taking your car to the shop. You will save money, learn more, and have a better built car in the long run.

If you don't like my advice then don't follow it but I don't see a positive outcome to trying to fight the shop on this one and overcharge them for the 2g bov.

 

[spicoli619]

OK on a happier note i finally fixed my over boosting problem. i did a boost leak test (so proud of myself haha) and found some small leaks. nothing to bad. mainly just on the boost controller. still need to change it to a MBC but I'm afraid to disconnect the stock one cause it has wires coming out of it and i don't know what to do with them. after the boost leaks i looked at the WGA and found that the mount that holds it was bent down, cause the little arm thing to be in contact with the mount. this made the arm not be able to move. which made my WGA not open i guess. and even to make sure it worked i put the HKS back on and it doesn't over boost. unfortunately i haven't made my recirculation kit so I'm not recirculating the air. will that cause any problems? i know you are supposed to recirculate the air and I will when i get the part made. but until then (about 2 weeks maybe) will it be OK to drive? or will it hurt my car. if it does ill change back to the stock BOV.
once again thank you so much for all your help guys. especially you mork. without the step by step and pictures i would have never been able to figure this out on my own.

 

[the_mork]

Not recirculating will hurt performance. The issue is that when you step on the gas pedal you aren't moving anything related to fuel, you are opening a throttle plate which increases the amount of air entering the engine. Your computer decides how much air is entering the engine by how much air passes over your MAF (the oval behind the filter) and injects a corresponding amount of fuel. If you vent then some of the air that is counted by the ecu never reaches your engine and you end up running rich. The computer will correct for this occasional rich condition globally so that sometimes you will run rich, sometimes lean, and never well. Some people vent and know the consequences and are ok with it but IMO you should work quickly to get your car recirculated. Again, this is a fairly recursive explanation just to make sure that everyone is on the same page.

As for the boost controller that is on your car, when you move to a manual boost controller you will completely unplug the vacuum lines from the BCS (the car's boost controller) but leave the wires plugged in.

Hope this helps.

 

[RD_Blade]

I'm not recirculating the air. will it be OK to drive?

Edit: Already answered.

I don't mean to argue with you over "good business", ...

I don't know, man. Pricing aside, what's right is right. They break the part, do a crappy improv on it, and don't tell the customer. If they really felt they're not responsible for it, then why try to cover it up and then stay quiet about it? In any business, shady practices like that are unacceptable...except on Wall Street, maybe.

 

[Dsmj89]

The mork is correct on his recirculaing post, but i just wanted to chip in about that problem with an hks bov.
The hks bov's spring is pretty stiff and doesn't leak boost at all, it is known to be one of the best bov's out there, my friend (which is registered on here chicken patty) runs an hks ssqv vented and never has had a problem with idle or driving.
It's not like the greddys that like to stay open for a long time before shutting and then re-opening once again.
Yes it is wrong to vent regardless, but i just wanted to throw that out about the hks. It's probably one of the only bov's you can vent without the real bad effect of idle vs other bov's.

 

[spicoli619]

OK cool i was reading how venting isn't as good as recirc but i couldn't find anything about it possibly hurting my engine. that is the main thing i was worried about. now that i know i feel better. and don't worry i will be recirculating. i have noticed my car has been running a little rich. and possibly found out why. on 97 talons, every time you turn the car off you reset your computer (making it really hard to smog i might add, still working on that) but i think since it resets every time the car is off it almost has to reprogram itself. don't know if thats why or not. but maybe. my car is a manual so I'm not to sure if the computer does a whole lot haha. I'm not much of an engine guy... more of a suspension person

 

[the_mork]

OK cool i was reading how venting isn't as good as recirc but i couldn't find anything about it possibly hurting my engine. that is the main thing i was worried about. now that i know i feel better. and don't worry i will be recirculating. i have noticed my car has been running a little rich. and possibly found out why. on 97 talons, every time you turn the car off you reset your computer (making it really hard to smog i might add, still working on that) but i think since it resets every time the car is off it almost has to reprogram itself. don't know if thats why or not. but maybe. my car is a manual so I'm not to sure if the computer does a whole lot haha. I'm not much of an engine guy... more of a suspension person

That should not happen. Also your computer does just as much as an automatic car's computer (which is a lot) because they are exactly the same, automatics have a different TCU.

This reinforces to me that you have some other issues that involve wiring (as we discussed elsewhere).

 

[spicoli619]

yea. the only reason i know it resets is be cause i had to go to the dealership and they say its like unavoidable. i dont know why they do it but from what the mitsubishi dealers said its a normal thing for these cars. but im not sure. it kinda concerns me as well

 

[the_mork]

What symptoms are you seeing from the resetting? I know that the readiness monitors on most 2gs have a tendency to reset with every key cycle but this is very different than the computer resetting, readiness checks are 99% for emissions compliance and wont really change how the car acts.

Also what are you using to check if your car is rich and how rich is it? The factory AFR maps are actually pretty poor and tend to be rich so that could easily account for your richness. Otherwise it could be related to your MAF problem.

 

[spicoli619]

it might be what you just said about the readiness monitors reseting and not the computer. i have an aftermarket air/fuel guage. but i dont know if it is working to well cause when im driving it never stays in the same place. it is always bouncing back and forth from lean to optimum. and then when i get on the throttle it goes rich.

 

[the_mork]

Do you have a wideband or a AF meter tapped into the stock o2 sensor?

 

[spicoli619]

i really dont know actually. since im not the one who put it on i dont know where it connects too. im terrible at wiring. but im gonna go get my car dyno tuned pretty soon. mabe they could tell me what is up with the air fuel mixture

 

[the_mork]

What are you using for tuning? You may have already told us and I've forgotten but I don't want to read through the whole thread again at this point.

It is important to know what type gauge you have (narrowband or wideband) if you take a picture of the gauge someone will probably be able to identify it. If it is a narrowband gauge then for our purposes it isn't useful. Narrowband o2 sensors are only useful with closed-loop/fuel efficiency/cruise tuning. If it is wideband then it will be quite useful but at this point I wouldn't be particularly worried about your momentary richness.

FWIW dyno-tuning is not a tuning method. When people talk about dyno-tuning they are talking about taking their car to a tuner that has a dyno and the expertise to tune the system that you already have in your car. Dyno tuning is generally more complete than road tuning because of the ability for the tuner to be able to simulate a number of scenarios and dial them in.

 

[spicoli619]

just a small update.. i believe that its my O2 sensor that is causing me to run rich and lean. (rich when WOT or even just hard on throttle) i just replaced all my plugs and wires. i got some E3 plugs and slight upgrade wires. (I'm not that rich ha ha) i heard the E3 spark plugs were the best so thats what i got. and it seems to run better. i also replaced all my belts except for the timing belt cause it is in perfect condition. next week ill be putting new oil in. any suggestions for what i should use? Ive been seeing alot of those castrol commercials i think it is. where the Irish guy slaps people with the dip stick and yells "Think with your dipstick... Jimmy!!" sadly yes that is the only way i can think of the oil, don't know the exact name but i believe its called castrol edge

 

[rEclipserGST]

just a small update.. i believe that its my O2 sensor that is causing me to run rich and lean. (rich when WOT or even just hard on throttle) i just replaced all my plugs and wires. i got some E3 plugs and slight upgrade wires. (I'm not that rich ha ha) i heard the E3 spark plugs were the best so thats what i got. and it seems to run better. i also replaced all my belts except for the timing belt cause it is in perfect condition. next week ill be putting new oil in. any suggestions for what i should use? Ive been seeing alot of those castrol commercials i think it is. where the Irish guy slaps people with the dip stick and yells "Think with your dipstick... Jimmy!!" sadly yes that is the only way i can think of the oil, don't know the exact name but i believe its called castrol edge

e3 plugs?! stop that. NGK wires and plugs all the way. Is your MAP sensor or MAF sensor any good? Check those.

 

[the_mork]

DSMs run rich from the factory, I see 10:1 commonly at higher loads.

The e3 plugs really aren't an upgrade over a good NGK plug.

Is your MAP sensor or MAF sensor any good?

A map sensor doesn't do anything except EGR function. My car until recently didn't even have one and it is now using one that doesn't come close to factory scaling (GM 3bar). Also for the record no DSM ever came with a MAP sensor, 2gs came with a MDP sensor. The only car AFAIK in our family that has ever had a MAP sensor is the JDM evo9 and now all evoXs have them but they are now a part of their own family (IMO).

 

[rEclipserGST]

DSMs run rich from the factory, I see 10:1 commonly at higher loads.

The e3 plugs really aren't an upgrade over a good NGK plug.

A map sensor doesn't do anything except EGR function. My car until recently didn't even have one and it is now using one that doesn't come close to factory scaling (GM 3bar). Also for the record no DSM ever came with a MAP sensor, 2gs came with a MDP sensor. The only car AFAIK in our family that has ever had a MAP sensor is the JDM evo9 and now all evoXs have them but they are now a part of their own family (IMO).

MAP - Manifold Absolut Pressure sensor
MDP - Manifold Differential Pressure sensor

Is that not the same thing? It definitely goes in the same place.

 

[the_mork]

MAP - Manifold Absolute Pressure, this measures pressure as compared to a complete vacuum.

MDP - Manifold Differential Pressure, this measures pressure as compared to atmospheric conditions.

MDP reads like your boost gauge, MAP reads like a barometer.

A 1 bar MDP sensor could read ~15psi of boost. A 1 bar MAP sensor can read up to 0psi. A 3 bar map however could read almost 30psi of boost.