Challenge Your Exam Readiness With Our Free T Series Practice Questions

Random misfire under heavy load points to insufficient fuel delivery or ignition breakdown at high demand. Slightly positive trims at WOT (where trims are limited but can still indicate trend) suggest the engine may be fuel-starved when airflow peaks. A dynamic fuel test—verifying rail pressure stability and pump volume under load—is the best next step. A cylinder leakage test (A) can reveal mechanical faults but typically causes consistent misfires, hot or cold, not only at high demand. EVAP purge (C) does not materially affect WOT operation, and purge is usually disabled then. A CKP scope at idle (D) won’t reveal high-load ignition stress unless there’s a synchronization fault; misfires only at load more commonly trace to fuel volume (plugged filter, weak pump) or coil insulation breakdown. ASE T1 objectives stress duplicating conditions: measure fuel pressure/volume during loaded acceleration or with a wide-open throttle test to isolate delivery limits before intrusive mechanical tests.