Hondata

Hi all,
Having some issues with my 09 Si recently. Had an issue where my car would randomly shut off on me while driving. When it would shut off it would be hard to restart and when it did start it would be when i pressed the gas to keep it on and sounded like a bad misfire that shook the whole car. Eventually driving it would smooth out and run normal again. This would happen more often and worse as time went by till it wouldnt smooth out any more. Thought the engine was toast so swapped out with new engine. Also put new oem crank sensor map sensor vtec solenoid put better grounds new harness swapped the ecu out for known good one and still same thing. I have a datalog but i dont know if it will show mechanical issue or tuning issue. Any help would be appreciated as this car has just been sitting for months.

When it starts running badly your battery voltage is not steady so you may have a wiring problem in the engine bay. It could be a ground or loose or corroded wires. This may be something that a tuner or mechanic may need to look at in person.

Oh man that makes absolute sense this whole time ive been looking in the wrong direction. Thank you! Im gonna test alternator, and check all my fuses and charge harness tomorrow and see what i find.