reving high when depressing clutch...

[mitch4712]

Well I spoke to soon it did it on my home from church. But not for as long as it used to do. If the plugs look as bad as the dist. Cap and rotor I bet they need changed. I'm going to check the plugs tomorrow.

 

[mitch4712]

I checked the plugs this morning. they all had a .056" gap. the sticker under the hood said they should be at .044 to .046 gap. would make a rough idle? Im going to change today. what plugs to you guys recommend? thank again for all your input. you guys have been very helpful.

 

[Rearanger]

Well I spoke to soon it did it on my home from church.

I guess god didn't believe you.

 

[Rearanger]

I checked the plugs this morning. they all had a .056" gap. the sticker under the hood said they should be at .044 to .046 gap. would make a rough idle? Im going to change today. what plugs to you guys recommend? thank again for all your input. you guys have been very helpful.

Check with plug manufacturer's web site to see what they recommend for the plug installed. If the gap has eroded from .045 to .056 then that would require more current to jump the gap, it could affect idle quality.

You seem to have two issues, rough idle and excessive high idle? Don't confuse the cause of one with the other.

It may be possible I guess that the IAC can be open enough to give a 2900 rpm idle with the throttle plate closed??? You may also have a worn throttle plate and or throttle plate shaft which could effect rpm idle.

 

[mitch4712]

I read on here somewhere that the IAC would only let the rpms go up to around 1800.
is there a way to check the signal for the IAC? to tell if its opening to far?

 

[RonD]

Use Motorcraft spark plugs if possible, AWSF-32PP
Yes, spec on gap is 0.044

No, no way to tell on the IAC, it uses a Stepper Motor, a step motor is controlled by a voltage pulse, like a Morse code in voltage pulses.
Computer sends a pulse to IAC motor, motor turns "X" amount opening or closing the valve, a different pulse turns "XX" amount, ect.......
Usually there are 100 to 256 "steps/pulses" the computer can use.

Best thing is to remove and clean IAC valve and before re-installing hook it up and turn on the key, motor should open valve all the way, for cold start, then unplug connector and IAC should close all the way, repeat a few times to see if it is sticking.

There is a Vent on the IAC, make sure this is clean and unrestricted, this vent equalizes pressure behind the valve so it can open and close easily, if vent gets clogged it can cause the valve to hesitate and stick.

 

[mitch4712]

Ok thanks ill check it out.

 

[mitch4712]

Ok so I removed the IAC and inspected it. it looks pretty clean. i hooked it up and turned on the key and It didnt look like it moved at all. the engine was warm but not at operating temp.

 

[Tractor Dan]

Motorcraft all the way on plugs. They have never failed me except for one i got that was bad out of the box. Had been dropped. Always best to check each of the new plugs at the store so if one has an issue you can get it swapped for a good one.

 

[mitch4712]

I got to looking at the iac again. Is valve suppose to close when it is unplugged?

When I unplug mine does not close. When I start the engine it takes awhile to idle down.

 

[mitch4712]

Bump.

 

[Rearanger]

I got to looking at the iac again. Is valve suppose to close when it is unplugged?

That would be my understanding. If it has a return spring it should close.

 

[mitch4712]

well I did a tune up one the ole b3000 and it seems to idle better. I one of the stems on the distributer cap was corroded. I still has a the issue with the high idle i think the IAC is bad. I noticed after i did the tune up when the engine is cold it has some hesitation in the 2k rpm range. Once it warms up it runn great. Oh and i got 21.7 MPG before the tune up.

 

[mitch4712]

Could low fuel pressure or a bad fill neck on the fuel tank cause rough idle?

 

[gvlgator]

2003 Ranger Edge - Similar Symptoms

My son had similar symptoms with his '03 Edge 5spd...high rpm idle and ZERO power available when using throttle. The telltale sign was that only the defrost would work regardless of switch position...wouldn't switch to dash or floor heat. I found a burned vacuum line between the "sphere" and the TPS. I repaired the vacuum line and saw immediate improvement with the heater, but the idle and throttle still screwed up and was undrivable.

After reading this thread and taking advice posted here, I took the opportunity to simply disconnect the battery. 10 minutes later, I connected the battery and started the truck. Apparently the ECM relearned the sensor responses and it ran like it was brand new...I never post here but always seem to find good advice. Thanks gents!