Fast Idle When Cold
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Joined: Dec 2000
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Fast Idle When Cold
I am in need of some advice before I start pursuing this issue. The truck is a '91 F150 with 351W and 175K miles. Now that the temps are getting cold in the morning I am having a problem with the truck idling much to fast.
Where to begin.
If I start the truck without at all touching the throttle it will fire and idle at a really low speed, just enough for it to keep running.
If I start the truck and just touch the throttle before turning it over it zooms up to 3000, then slowly drop to 2000 RPM and will stay there until at full operating temperature.
I made the mistake of trying to "blip" the throttle to get it to kick down, but that made it fly up to about 4500, then slowly come back to 2000.
This is really unnearving, especially when cold starting the truck on these 10 degree F mornings.
I have replaced most of the exhaust over the summer, headers, high-flow cat, and larger pipes. New 02 sensor, EGR position sensor, disassembled and cleaned the throttle body. New plugs, wires, cap & rotor.
Does this sound like idle solenoid sticking problem? If so, where is that located that I might check it, or replace it?
Any advice will be greatly appreciated.
Tim
Where to begin.
If I start the truck without at all touching the throttle it will fire and idle at a really low speed, just enough for it to keep running.
If I start the truck and just touch the throttle before turning it over it zooms up to 3000, then slowly drop to 2000 RPM and will stay there until at full operating temperature.
I made the mistake of trying to "blip" the throttle to get it to kick down, but that made it fly up to about 4500, then slowly come back to 2000.
This is really unnearving, especially when cold starting the truck on these 10 degree F mornings.
I have replaced most of the exhaust over the summer, headers, high-flow cat, and larger pipes. New 02 sensor, EGR position sensor, disassembled and cleaned the throttle body. New plugs, wires, cap & rotor.
Does this sound like idle solenoid sticking problem? If so, where is that located that I might check it, or replace it?
Any advice will be greatly appreciated.
Tim
Postmaster
Joined: Jul 1999
Posts: 3,172
Likes: 4
Fast Idle When Cold
More than likely the Idle Speed Control is carboned up . Cold weather makes problems with carbon 10x worse . It sounds like the throttle plates are sticking some too . It really doesnt take much to raise the idle speed . Clean both the throttle plates & the idle speed control & see how it responds .
