Stalls at Idle No codes.
#1
Stalls at Idle No codes.
I imagine this is the usual IAC problem, but just wanted to confirm with you guys if that's all right:
My buds 2003 4.6 liter stalls every time he takes his foot off the pedal. Runs fine otherwise, no roughness or anything, you just have to keep your foot on the thing to keep it from dying out.
We checked for codes and found none. I checked vacuum connections and they looked OK.
Is there an easy way to test the IAC or should we just throw a new one in and cross our fingers? If we do change it out, does the truck need to be driven around a bit for the computer to re-learn anything?
Many thanks in advance for any help.
My buds 2003 4.6 liter stalls every time he takes his foot off the pedal. Runs fine otherwise, no roughness or anything, you just have to keep your foot on the thing to keep it from dying out.
We checked for codes and found none. I checked vacuum connections and they looked OK.
Is there an easy way to test the IAC or should we just throw a new one in and cross our fingers? If we do change it out, does the truck need to be driven around a bit for the computer to re-learn anything?
Many thanks in advance for any help.
#2
#4
#5
Any ideas?
#6
On your Expedition it would never be the crank sensor if the engine starts at all.
There is an issue within the cold start sequence.
There is a lot that goes on.
The IAC has to open, the ignition timing has to advance and fuel has to go rich.
This all happens when the key goes to Run before cranking, by the computer looking at the values of the cylinder head temperature and intake air temperature sensors as the signals it's to be a cold start.
After starting, the idle should go high then slowly come down as the engine heats and Ox Sensors take control of fuel injection levels.
The fuel will remain somewhat rich until the coolant temperature begins to climb as the thermostat opens, then leans down.
A Scanner looking at live data may see something out of normal range.
The fuel pressure may also be low as a cause of stalling.
Good luck.
There is an issue within the cold start sequence.
There is a lot that goes on.
The IAC has to open, the ignition timing has to advance and fuel has to go rich.
This all happens when the key goes to Run before cranking, by the computer looking at the values of the cylinder head temperature and intake air temperature sensors as the signals it's to be a cold start.
After starting, the idle should go high then slowly come down as the engine heats and Ox Sensors take control of fuel injection levels.
The fuel will remain somewhat rich until the coolant temperature begins to climb as the thermostat opens, then leans down.
A Scanner looking at live data may see something out of normal range.
The fuel pressure may also be low as a cause of stalling.
Good luck.
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