High Idle
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High Idle
I have a 1996 F250 with the 5.8 liter engine. The engine idles fast. I have replaced the idle air control valve with a Motorcraft valve. I also searched for vacuum leaks and could not find any.
Edit*
I almost forgot to add. The truck won't is hard to start. The only way to get the engine to start is to press the throttle all the way to the floor. Pumping the throttle will not work. When the truck starts you will get black smoke from the tailpipe. I was under the impression holding the throttle to the floor while cranking cut fuel to the engine. I'm not sure why the engine is flooding over.
The engine fires up almost immediately when I unplug the mass air flow sensor. With the mass air flow sensor unplugged the engine will idle at a better speed. However the engine will not slow down after you speed it up without load.
I could use some ideas and information on how to troubleshoot this problem. Thanks!
Edit*
I almost forgot to add. The truck won't is hard to start. The only way to get the engine to start is to press the throttle all the way to the floor. Pumping the throttle will not work. When the truck starts you will get black smoke from the tailpipe. I was under the impression holding the throttle to the floor while cranking cut fuel to the engine. I'm not sure why the engine is flooding over.
The engine fires up almost immediately when I unplug the mass air flow sensor. With the mass air flow sensor unplugged the engine will idle at a better speed. However the engine will not slow down after you speed it up without load.
I could use some ideas and information on how to troubleshoot this problem. Thanks!
Junior User
Joined: Apr 2013
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Hey i had the same problem, then I replaced the idle air control valve. It still did it so we sent it in and they replaced the idle air control valve again with one from FORD. They said some things have to come from ford and that that was one of them. I hope this helps.
Postmaster
Joined: Nov 2011
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From: SW Florida
Do you have a Check Engine light on? Even if you don't, pull the codes and post them here (the actual code, not the description). If you don't have a code reader, AutoZone will read them for free. For whatever fault code you get, they might try to sell you a replacement sensor/actuator, but DON'T buy it yet! The codes point to the device that sees the fault, not necessarily to the actual cause of it.
Fleet Owner
Joined: Oct 2005
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From: Kentucky
Do not let them install and charge you for these sensors unless they followed the correct testing procedure.
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The only thing the shop installed was a new fuel filter.
The shop foreman said that when unplugging the coolant temp sensor and plugging in a scan tool the computer would read ~160°. He said that generally Fords will read at -40° unhooked and 300° with the connector jumped and the he thought I have a bad spot in my wiring.
The shop foreman said that when unplugging the coolant temp sensor and plugging in a scan tool the computer would read ~160°. He said that generally Fords will read at -40° unhooked and 300° with the connector jumped and the he thought I have a bad spot in my wiring.
Fleet Owner
Joined: Oct 2005
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From: Kentucky
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