OBE1 95Z28
08-22-2005, 10:34 AM
Background: I've got a 10# intercooled Vortech setup on a 355 with a 218/230/114LS cam, ported LT1 heads and a BBK 52mm TB. Car runs good but I needed to upgrade my 36 #/hr injectors. Just switched to 75 #/hr Delphi injectors with the Acceleronics converter box. Car was dyno/wideband O2 tuned yesterday.
Issue: Engine can't maintain idle (IAC wide open at 160); idle programmed at 775 rpm and engines idles at 550 rpm. The BBK 52mm TB has the idle "breather" hole like the stock TB, with an opening of approximately 5/64". My tuner suggested that I enlarge this hole to correct the idle; through several iterations, I've enlarged the hole to 7/32" (about 5 drill sizes bigger) and when warm the engine now maintains idle with an IAC count in the mid 70's. When cold, the IAC still rails at 160 with a 550 rpm. Has anyone elso performed this mod to correct for idle?
Second issue: Car starts first time when cold, but once the engine is up to operating temperature, it won't start unless I hold the gas pedal to the floor (flood mode start). Suggestions?
Issue: Engine can't maintain idle (IAC wide open at 160); idle programmed at 775 rpm and engines idles at 550 rpm. The BBK 52mm TB has the idle "breather" hole like the stock TB, with an opening of approximately 5/64". My tuner suggested that I enlarge this hole to correct the idle; through several iterations, I've enlarged the hole to 7/32" (about 5 drill sizes bigger) and when warm the engine now maintains idle with an IAC count in the mid 70's. When cold, the IAC still rails at 160 with a 550 rpm. Has anyone elso performed this mod to correct for idle?
Second issue: Car starts first time when cold, but once the engine is up to operating temperature, it won't start unless I hold the gas pedal to the floor (flood mode start). Suggestions?