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-   -   wrx/sti idel problems and stalling issues (http://www.wrxtuners.com/forums/f72/wrx-sti-idel-problems-stalling-issues-29481/)

bjohnson991 09-12-2010 12:55 AM

wrx/sti idel problems and stalling issues
 
i bought a 2004 wrx with a 2005 sti engine in it. its a brand new engine with only 3000 by the previous owner. i picked the car up from Chicago and drove it back to northern Michigan just fine. now all of a sudden it doesn't want to stay started. i start it and it starts normal (rpm go to about 2k) then when there coming back down it just stalls. i havent drove it hard at all. i took it to a shop and they put a pressure gauge in the fuel line and it was only reading 38 psi and when i give it a little gas they drop to about 30psi. these are all the mods done to it and all done professionally

Engine: EJ25 - STI 2.5 ltr
CP pistons - All work performed at Apex Engineering
860CC Fuel Injectors
Walbro 255 lph Fuel Pump
Perrin 4-2-1 headers, along with a 3 inch Turbo back - HKS Dragger
HKS SS blow-Off Valve with Grimmspeed hoses
Aftermarket Intake
Exedy Stage 2 Clutch - Just broke in
Flash AWD dyno tuning performed at - Benchmark Tuning - 308 lb/ft torque and 294 hp on 93 octane at 18lbs boost

possible problems i found are: fuel pump, fuel pressure regulator, spark plugs, or o2 sensor


any ideas would be alot of help. thanks

mfarnham 09-12-2010 08:24 AM

I had the same problem with an older car of mine. Just needed new plugs. But full atmospheric blow off valves can cause problems with idling and stalling as well. That shouldn't be the problem right now though, considering you can't even give it gas. Might need a new fuel filter or fuel sensor.

newtothegame 09-12-2010 10:14 AM

Give Mat or Sean at Benchmark a call/email. They are great guys. I will be picking my car up from them next month someitme. But I would start with the spark plugs. Also go through and make sure you have no leaks, nothing disconnected. Start with the small stuff.

wagonracer 09-12-2010 10:58 AM

That sounds like a big (metered or pre-MAF) air leak to me. I'd check intake all the way to throttle body including vacuum lines for tears, hose disconnected etc. I've had other cars (non subies) behave the same way when they had a tear in the intake hose. However, the fuel pressure doesn't sound right either. What's the pressure supposed to be on an EJ257 ?

bjohnson991 09-12-2010 06:41 PM

i dont know what the fuel pressure is on these cars. i took it out for a drive to see if running it for a bit would mabey clear things up in it. it spits and spudders in the low rpm's then its better in the higher ones but when you shift its back to spittin. almost like its not getting enough fuel to run the engine.

basco 09-12-2010 06:50 PM

like wagon said...that sounds like a BIG Intake leak

bjohnson991 09-12-2010 06:59 PM

okay so look from the after market air filter all the way into the engine?

bjohnson991 09-12-2010 07:19 PM

hey thanks for the tip on benchmark tunning. i emailed them and in a matter of minutes a guy called and he had me unplug the mass airflow censor and it started right up and ideled fine. i indeed has a intake leak somewhere

wagonracer 09-12-2010 07:37 PM

Any check engine light ? Yes, inspect from filter back to the turbo. It doesn't sound like a post-turbo issue. Have you searched for fuel pressure specs ?

RcrsWetDream 09-12-2010 08:27 PM

Stock fuel pressure should be 43.5 psi correct?

bjohnson991 09-12-2010 09:53 PM

this is whats up with the ol girl. it was tunned by benchmark tunning and when they tunned it, its not suppose to has the mass air flow censor hooked up becasue it is tuned for without it. so someone hooked it back up and thats why it wasnt running properly. i called the previous owner (we speak every now and then about it) and he told me to disconnect it and it runs like a dream:) ill will make sure to put pics up of it sometime.

newtothegame 09-12-2010 10:37 PM

Glad to hear you got everything all figured out.

man show 09-13-2010 11:18 AM

Thank goodness for easy fixes. Anxiously awaiting pics...


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