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Old 10-18-2007, 10:26 AM
wbrian63 wbrian63 is offline
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Join Date: Aug 2006
Location: Houston, TX
Posts: 450
lazy electronic throttle

'92 300SE. On occasion, it seems like the electronic throttle actuator is "lazy". Most of the time I drive the car very sedately, as it does very little good to flog a big beast with a little motor.

However, on occasion, I do need a little "giddy-up" off the line. (You can tell I'm from Texas...) Tromping on the throttle from stop occasionally produces a huge amount of acceleration when the car downshifts to first gear. However, most of the time, there's a noticeable lag before the motor really starts to rev.

With a high 3: rearend and a high 3: first gear, even this 2+ ton beast should move smartly off the line in first gear with big throttle.

I remember on my older cars with carburetors, they usually performed best when you didn't stomp on it off the line, but jump to about 1/2 or 2/3 throttle and floor it once moving a bit. I've tried that technique as well - same results - noticeable lag, then o-baby, hold on.

Because it occasionally rockets like I think it should, I'm thinking that maybe the throttle actuator is "lazy" - slow to react.

The last time I pulled codes on the car, I got nothing back. This problem has been persistent for the last year or so, and I've pulled codes since then, so I'm not inclined to believe that I'll find codes if I scan today.

Any suggestions for diagnosis or testing?
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