CAMARO6 - View Single Post - bad idle and waving part throttle acceleration

bennettbrowder3 · 08-15-2024, 08:34 AM

Ive got a Max effort 416 engine with all the bells and whistles, big cam, heads, 2inch kooks headers, ATi dampener, BMR engine mounts, Monster triple disc clutch, MM mild Catch can, GPI plug wires, New O2 sensors, NGK plugs, ported/spacered Hiram, Lt4 injectors and HP pump, NW TB, and OTR air intake. Built and tuned by Pray Performance. Runs on pump E85. It has ran great for 2000 miles, but has recently developed a dipping idle when cold, and is getting worse. It dips so low that it almost dies, but mostly clears up after its warm. On part throttle accel it waves back and forth, like Waaah waaah, waaah. Even with constant pedal, it feels like your leting off the gas and back on. WOT is not affected. I have checked Hiram,TB torques, sprayed Carb cleaner all over the Hiram and Vac line connections multiple times, but cannot find a Vac leak. Recorded a log yesterday and had P0300 random missfire, TB % at idle bounced between 17-22, and Longterm fuel trim was -9 and -10. Sounds and acts like a Vac leak.....but i cant find it?? Anyone??

08-15-2024, 08:34 AM	#1
bennettbrowder3 Drives: 2018 2SS 1LE 416 NA Join Date: Feb 2021 Location: Savannah GA Posts: 38	bad idle and waving part throttle acceleration Ive got a Max effort 416 engine with all the bells and whistles, big cam, heads, 2inch kooks headers, ATi dampener, BMR engine mounts, Monster triple disc clutch, MM mild Catch can, GPI plug wires, New O2 sensors, NGK plugs, ported/spacered Hiram, Lt4 injectors and HP pump, NW TB, and OTR air intake. Built and tuned by Pray Performance. Runs on pump E85. It has ran great for 2000 miles, but has recently developed a dipping idle when cold, and is getting worse. It dips so low that it almost dies, but mostly clears up after its warm. On part throttle accel it waves back and forth, like Waaah waaah, waaah. Even with constant pedal, it feels like your leting off the gas and back on. WOT is not affected. I have checked Hiram,TB torques, sprayed Carb cleaner all over the Hiram and Vac line connections multiple times, but cannot find a Vac leak. Recorded a log yesterday and had P0300 random missfire, TB % at idle bounced between 17-22, and Longterm fuel trim was -9 and -10. Sounds and acts like a Vac leak.....but i cant find it?? Anyone??