I inherited a 92 F150 several months ago (4.9L, 5 speed), and am still getting used to its little habits. One thing I'm having trouble getting used to is that the engine really revs shortly after starting, especially when it's cold. This is my first EFI vehicle, so I'm learning as I go. Is this the normal routine? Thanks for the info!

 

When I start my truck on a cold morning it will go to ~2000 rpm for a second, then drop down to 1200 rpm, that's known as "fast idle" or the automatic warm up that the trucks computer does, normally its good to let it idle for about 5 seconds before pulling out (I'm not sure on how long to let it idle, but thats what I do)

1995 F-150 XL Reg Cab/Bed
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5-star rated F-150 (big stereo)

 

You didn't say how many miles are on your truck. I would guess that your idle air bypass valve is dirty and it is sticking open too much. These cause alot of problems if they are dirty. There are two bolts holding it on to the thottle body. I'd take it off and see if there is alot of carbon in it. The manual says to replace it and not clean it, but I've had three of these trucks, and I've cleaned the valve carefully with carb cleaner. Just make sure not to get any cleaner into the electrical part of the valve.

 

All,
Thanks for the info. Kevin, that's exactly what it does, and I kind of suspected that it was a "programmed" event. It just makes the hair on the back of my neck stand-up to hear a cold, just-started engine rev that much. I don't have a tach (yet...), so I'm not sure exactly how high it goes.

By the way, sorry for the lack of background info. The truck has about 90 kmi on it, and runs great.

 

My '95 F150 300 I6 revs to about 1800 on startup then drops back some to maybe 1400 or 1500 for a few seconds. Usually after about 5 seconds or so will drop to around 1000 or 1100 and that's when I go. I believe this is all normal. You want a high idle on startup because that way your oil pump is running faster to get that oil to the bearings quicker.