Help back fires under boost

[molotovman]

when i get into boost it starts backfiring, i was told that it had something to do with my BOV and recirculator, i was also told that i might need a mass air flow conversion? can someone explain this to me, I am a turbo newb so i have no idea what they are talking about

 

[sicktsiboy]

Are you running the stock T25??? check for boost leaks and at what psi is it causing it?

 

[molotovman]

^^^ at i believe 8 PSI after 5500 RPM's
TD05 16G evo3
i just had the engine rebuilt, and a new turbo installed.
hks SSQV BOV

 

[viperlp01]

You need to fill out your profile and what psi are u running

 

[bslavsGSX]

Check for boost leaks , also what injectors are u running, maybe u need a tune..

 

[2gjlc]

8 PSI with a 16g? Its probably a boost leak and you should seriously consider recirc'ing your BOV.

 

[molotovman]

stock injectors, how do i recirculate my blow of valve, im a newb please explain
mods are
-Evo 3 16G Turbo
-B&M Short shifter
-INJEN plug cover
-Hard intake pipes
-Stage 2 Clutch
-Fluidyne Performance radiator
-2" drop springs
-18" urban racing wheels, With new tires
-HKS SSQV BOV
-Boost gauge
-Pioneer speakers
-Pioneer Head unit
-Viper alarm

 

[brian9397gsx]

there is a kit to recirculate your ssqv eBay Motors: HKS SSQV BOV Recirculation Fitting PN 71002-XA001 (item 280322807244 end time Apr-13-09 10:05:48 PDT)

 

[brian9397gsx]

eBay Motors: HKS - SSQV Recirculation Kit - Mitsubishi Eclipse 95-99 (item 370182131553 end time May-01-09 07:54:06 PDT)

even better one

 

[MIenKEi446]

I think its because youre venting your BOV, check the MDP sensor. Just go to Autozone and run the OBD2 it should come up at something like P1400, thats what was wrong with my car.

 

[viperlp01]

An injen spark plug cover adds like 10 hp ... Im just messing with ya... I bet its a boost leak...

 

[molotovman]

the only codes its trowing are to the O2 sensor
does recirculating the BOV sound about right then?

 

[Dsmj89]

+1 for boost leaks.
1 - Change your o2 sensor. A faulty o2 can cause poor gas mileage and poor part-throttle driving and overall performance.
2 - Check and make sure all your couplers are tightened well.
3 - You might want to look into getting one of the above posted recirculation kits for your bov.
4 - Change you spark plugs and spark plug wires if you haven't already done so.
5 - Get your supporting mods for the turbo (550cc or 650cc's and a 190 or 255 fuel pump). If you can't afford these right now keep boost below 10 psi.
6 - And lastly, get some type of tuning device for your car. At this point i hope you have a wideband to use for tuning, that way you don't tune too lean or rich.

 

[nytescion]

huuuu. its not the bov unless its happening when you let go of the throttle. is it happening during boost? is the boost cuttting out also when it backfires while boosting? if so check your mas is working and for boost leaks.

 

[Dsmj89]

The bov is not going to cause his mentioned problem but if you think of it, it's dumping metered air, which in turn is causing him to run rich, therefore, it's just taking a bigger punch on his already failing o2 sensor.
As good as the hks bov is in holding boost and not leaking, there is a reason mitsubishi engineers designed the recirc. pipes for our cars, to recirc the bov back into the intake, regardless of the bov used.

 

[molotovman]

huuuu. its not the bov unless its happening when you let go of the throttle. is it happening during boost? is the boost cuttting out also when it backfires while boosting? if so check your mas is working and for boost leaks.

i floor it after 5500 RPM it feels like it reaches the rev limiter and the BOV goes crazy. I am assuming it is backfires, i usually let off the gas when it does this since im scared to blow the engine.

during idle where should my boost gauge read?

 

[Silver99GSX]

I would Check for a boost leak, What kind of Fuel management are you running?

 

[MIenKEi446]

Well for one it should read in the Vacuum around 25: or so, my car is on blocks getting a new clutch so i cant check now

 

[Dsmj89]

At idle, a normal reading would be anywhere in the area of 16-18 of vac.

 

[molotovman]

my car reads 16-18 of vac with poor bouncy idle, also no Fuel management.

 

[Dsmj89]

Are your spark plugs good ? Have you checked them out ? Are they correctly gapped ?
What rpm do you idle at ?

 

[molotovman]

Are your spark plugs good ? Have you checked them out ? Are they correctly gapped ?
What rpm do you idle at ?

plugs are good, rpm jumps from 750-900 give or take

 

[Dsmj89]

Have you ever replaced your pcv valve ?
I remember replacing my pcv valve before on my previous gst as well as other small things and it helped greatly with my idle.

 

[Imback]

What type of plugs are you using ?

 

[gofer]

your car idles rough because your bov isn't recirc'd. when your turbo is in vacuum (idle or not under load) your bov is forced open, not a lot but it is open. the air coming into the motor is seen at the intake but disappears before it gets to the intake manifold because your bov is releasing it into the atmosphere and not back into the system. your motor is doing this all the time wondering where all its air is going... its a $25 piece thats needed when running any kind of bov on a DSM. heres a picture of mine recirced and what it should look like...

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ignore the white powder, my car caught on fire and co2 makes a big mess.

now for the 5500rpm bov stutter/backfire. its hard to tell whats happening under boost inside your motor unless you get some kind of logger. since you don't have a fuel management system OR a logger id suggest saving for dsmlink, it does both for you and the install is plug and play once you get a eprom ecu. since your running 8lbs of boost at 5500rpm im going to say that your running rich. theres to much fuel in the motor and not enough air being pushed in by the turbo, id turn the boost up to at least 12lbs since that what your car runs in stock form to see if it corrects the problem... if not just don't get into the throttle until you get the supporting mods for your bigger turbo and get it on a dyno to get tuned. its still driveable once you get a recirc pipe on your bov, just not raceable...

and get a battery tie down while your at it, thats why my car caught on fire. the battery shorted to my strut tower brace on christmas eve. that was the DSM gods telling me i was being an idiot so don't make the same mistake...