I noticed the other day when I let off the gas and am coasting, the tach (engine speed) more or less stays where it was and starts to gradually drop as vehicle speed drops. Then when I come to a complete stop it is almost as if the braking action pulls the tach (engine speed) down to about 600 rpms before the transmission will release the engine, after I come to a stop the rpms rise up to about 750. I would understand this with a manual but, it just doesn't seem right with a auto. I would think when you let off the gas and start coasting the rpms would drop to near idle level. Am I imagining a problem or do I have a problem? Thanks.

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Y2K Lariat Flareside SC
5.4, 3.55 Limited Slip
Class III Towing Package
6 Disc CD Changer
Captains Chairs
Bright Red over Silver


MODS:
Bugflector II
Herculiner Bedliner
Clear Corner Lenses
Ford Oval Hitch Cover
Custom Scratched Tailgate

Future mods:

Superchip, Airaid FIPK, exhaust and ss nerf bars.

 

You are dealing with torque convertor lock-up. It's locked and kind of stalls the engine out sometimes when you stop. Mine does the same thing. The rev thing, it's the way it should be. I've never driven any auto's where it dropped to idle off throttle. If you go into neutral yea, but not in drive. The engine is connected through the convertor, and when it's locked, it has to turn a certain RPM, which is depentdant on gearing. Correct me if I'm wrong here people..

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2000 F150 XLT 4x4 Short Bed. Amazon Green, 5.4L, SuperCab, ORP, Tow Package, Sliding Rear Window, Electronic Shift, Keyless Entry, LT265-70-17 Tires, Clarion Pro Audio, Herculiner Bedliner, Air Silencer Removed.

1994 SVT Mustang Cobra. #1032 of 6009. Black coupe with black leather int., 3.73 rear, Bassani Exhaust, Aluminum D/S, Bridgestone RE-71 255-45-ZR17

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Thanks for the info, this is the first vehicle I have owned that has a auto and a tach. For some reason it just caught my eye the other day. Thanks again!