Accordion Hose

MA70-3.0GT · 03-13-2013, 08:09 PM

If you have a turbo? The recirculating BOV could have been replaced with an atmospheric BOV (PSHHHH! noise letting off the gas?).
Few more details of the car would help & a pic of the hole you're talking about, if it IS the BOV replacement this can cause rough running in 3 ways.

First way is if the wrong type is fitted (cheap single piston BOV will cause a vacuum leak at idle, you need either recirc. or twin piston) or if the original has just had one end disconnected.

Second is if you have a twin piston that's not sealing for some reason (some are adjustable, or secondary piston could just be stuck or leaking)

Third reason (less likely) is with atmospheric BOV's, when you let off the throttle from high boost situations the engine can run rich momentarily due to the (already metered by the AFM) boost air being vented instead of making it into the motor.

HTH

P.S. Pandrade, the other hole under the accordion hose is power steering full lock idle-up valve IIRC

03-13-2013, 08:09 PM	#3
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	If you have a turbo? The recirculating BOV could have been replaced with an atmospheric BOV (PSHHHH! noise letting off the gas?). Few more details of the car would help & a pic of the hole you're talking about, if it IS the BOV replacement this can cause rough running in 3 ways. First way is if the wrong type is fitted (cheap single piston BOV will cause a vacuum leak at idle, you need either recirc. or twin piston) or if the original has just had one end disconnected. Second is if you have a twin piston that's not sealing for some reason (some are adjustable, or secondary piston could just be stuck or leaking) Third reason (less likely) is with atmospheric BOV's, when you let off the throttle from high boost situations the engine can run rich momentarily due to the (already metered by the AFM) boost air being vented instead of making it into the motor. HTH P.S. Pandrade, the other hole under the accordion hose is power steering full lock idle-up valve IIRC __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!! Last edited by MA70-3.0GT; 03-13-2013 at 08:11 PM.