Engine Controls - Hesitation Accelerating From a Stop
NUMBER: 11-77-05DATE: 09/08/05
APPLICABILITY:
2006MY Forester and Impreza 2.5L SOHC, Non-Turbo vehicles
SUBJECT:
Hesitation or Poor Performance from a Stop
INTRODUCTION
During your road test when performing PDI, if you notice hesitation from a standing start after the engine is warmed up there is the possibility that the ignition timing learning was not finished completely. With that condition you would experience hesitation during acceleration due to temporary engine torque stopping when the valve lift of the variable valve lift mechanism is changed from Lo to Hi. The hesitation can be cured by performing the promotional learning method for the ignition timing.
REPAIR PROCEDURES/INFORMATION:
Promotional Learning Methods for the Ignition Timing
AT vehicles (There are two methods either may be used)
(A) Method by Stall
(1) Warm the engine up until the radiator fan comes on.
(2) Engage the parking brake and fully depress the brake pedal, put the transmission in drive "D" range, then fully depress the throttle pedal for five seconds.
(3) Put the transmission in neutral "N" range, let the engine cool down for at least five seconds.
(4) Repeat steps (2) and (3) four times.
(B) Method by driving on road;
(1) Warm the engine up until the radiator fan comes on.
(2) Put the transmission in 2nd gear and accelerate from 0 mph, WOT (Wide Open Throttle) to 35 mph (about 3,200 rpm)
(3) Repeat step (2) five times.
MT vehicles (driving on road only)
(1) Warm the engine up until the radiator fan comes on.
(2) Put the transmission in 3rd gear then accelerate from 25 mph (about 2,000 rpm) with WOT (Wide Open Throttle) to 40 mph (about 3,200 rpm)
(3) Repeat step (2) five times.
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