stumbles on deceleration??
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FTE Chapter Leader
Joined: May 2001
Posts: 3,322
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From: Rhode Island
stumbles on deceleration??
my truck has had a problem with deceleration for a while now. but its even worse now, with a new timing chain, water pump. I still have to do a tune up on it, plugs, wires, cap, and rotor. I was curious if anyone out their had or has the same problem?
I have an 8/85 F-250 4x4 6600gvwr. Fuel injected. 5.0
Either at idle or at speed the truck is great, especially with the new timing belt. But when you decelerate, for instance, I rev the engine. And when the engine decelerates it wants to stall, but then just about at stall it revs up to idle speed again? It does the same thing when im slowing down to a stop. And to top things off, because the idle gets so low on deceleration , if I happen to be turning into a street or a driveway, the truck has a tendancy to stall completely????
Any one ever have this problem with their truck????
I have an 8/85 F-250 4x4 6600gvwr. Fuel injected. 5.0
Either at idle or at speed the truck is great, especially with the new timing belt. But when you decelerate, for instance, I rev the engine. And when the engine decelerates it wants to stall, but then just about at stall it revs up to idle speed again? It does the same thing when im slowing down to a stop. And to top things off, because the idle gets so low on deceleration , if I happen to be turning into a street or a driveway, the truck has a tendancy to stall completely????
Any one ever have this problem with their truck????
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Joined: Jan 2001
Posts: 56,997
Likes: 2,743
From: Virginia
stumbles on deceleration??
Tear the throttle body and IAC valve apart and clean them up. Also, with the truck idling, unplug the IAC valve connector. The truck should slowly die. If it quits a soon as you unplug the connector, your idle stop screw is backed off too far. If when it's un-plugged, the truck keeps running, then the idle screw is turned in too far. Remember, the idle screw on the throttle cable does not control the idle on a fuel injected vehicle, just the minimum air through the throttle butterfly(which can be messed up if it's dirty). The IAC valve controls the idle speed, with instruction from the computer.
