Matticus
Full Access Members
I had the motor swapped in my 2012 expy about 6 months ago. Shortly after the swap, I've noticed a sort of "lunge" and also hesitation when accelerating with light throttle from a stop through at least the first three gears - always between ~1300 - ~1700 rpm. I'll lightly press the throttle to leave a stop light and it will often lunge a little above 1700, then shift into second and suddenly feel like it's got half the power, then suddenly pick up power again right before it shifts...usually feeling like the engine just falls flat. When I cruise around 50 - 60, it seems like it continues to surge repeatedly ever so slightly. Other than than, runs awesome. Give it substantial amount of throttle and it's flawless.
At first, I thought the trans was shifting too soon/getting confused or something because it seemed like it would immediately downshift when the engine would suddenly fall flat. But, I've been driving around with my torque app open and watching the throttle position data. I'll push the throttle until it reads between 25% - 30% and hold it there. When that hesitation occurs, I often see the percentage jump clear up to 40 or 50% even though my foot is in the exact same position.
Does this sound like the throttle position sensor? It would make sense that both the trans and air/fuel ration could get mixed up if the TPS is saying it is in a different position than it really is. Any sure fire way to check or should I maybe just throw a new TPS at it and see what happens?
EDIT: This lunge/hesitation seems to manifest itself mainly when the vehicle is up to temp. Doesn't seem to do it on cold start
At first, I thought the trans was shifting too soon/getting confused or something because it seemed like it would immediately downshift when the engine would suddenly fall flat. But, I've been driving around with my torque app open and watching the throttle position data. I'll push the throttle until it reads between 25% - 30% and hold it there. When that hesitation occurs, I often see the percentage jump clear up to 40 or 50% even though my foot is in the exact same position.
Does this sound like the throttle position sensor? It would make sense that both the trans and air/fuel ration could get mixed up if the TPS is saying it is in a different position than it really is. Any sure fire way to check or should I maybe just throw a new TPS at it and see what happens?
EDIT: This lunge/hesitation seems to manifest itself mainly when the vehicle is up to temp. Doesn't seem to do it on cold start
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