Almost Stalling

[curtie94]

Hi I have been having some really weird idle problems, some have been there since I bought the car and others come and go. First off the car has 173,000 miles.

Things I've done:
Clean IACV, FITV, TB
Replaced o2 Sensor, but it is a universal one.
Alternator
Checked and cleaned every ground I could find, I bet I missed one
Replaced coolant

Heres what It does:
It idles rough at idle and gets rougher when I turn on headlights, rear defroster, really any electrical load, even the power windows.

Lately when I push the clutch in or put it in neutral the idle drops way down to like 550 rpms then jump back to 900 then back to idle at 750.

Sometimes it also doesn't drop below 1100 rpms, but If I grab the back of the pedal with my foot the idle will drop, but again down to like 550 rpms.

What does this sound like to you.

[deevergote]

My first thought goes to the clutch switch, thinking maybe something in that circuit is grounding out. That's not much more than a guess, though.

Are there any funny noises?

[xkjnboix]

any CEL's??
did you screw the FITV thing all the way down ??
are the symptoms happening when the engine is cold or normal op temp ??
what engine do you have ??

Bleed the coolant system again ( be sure your heater is on blast ), replace your NGK sparkplugs ( 8$ total for 4 V powers ), dump a full can on Chemtool B12 ( 3.50$ ) in your gas tank, and adjust your idle screw so you idle at 900-1.1k with a/c on blast and headlights on.

it does however sound like your clutch switch is sticking or faulty. ( everything else i suggested is general maint. & wont hurt your car or problem its having. its inexpensive and can do nothing but help )

If you turn your A/C or headlights on and your idle doesnt even out then your IACV is going out. There is a trouble shoot to check if its functioning properly in the shop manual.

[curtie94]

The engine is a f22a1 no cels and yes I screwed it all the way down.

[curtie94]

My first thought goes to the clutch switch, thinking maybe something in that circuit is grounding out. That's not much more than a guess, though.

Are there any funny noises?

The cruise control works flawlessly would that rule that out? and as for the funny noises there is nothing out of the ordinary.

[xkjnboix]

do everything i listed above before or after you replace the clutch switch. i do this because you might not have the $$ for a switch atm and those few little things might solve the problem.

if your clutch switch is sticky then it would always think its depressed meaning the cc would work flawlessly anyways. if it didnt disengage immediately after cc is set then that is one way to test your switch but wont necessarily mean its good just because it worked 1 or 2 times fine.

[curtie94]

Ok would that mean I could start it without pressing the clutch, because I can not.

But when I press the clutch when cruise control is on the rpms jump up then drop back down.

[xkjnboix]

if its stuck in the engaged position then cc would work fine but you still wouldnt beable to start your car with it stuck on engaged. but your rpms with the cc acting funny like you say then i would just replace the switch. something cheap and questionable like that i would just simply replace it.

[Dr. Shuffles]

Check your alternator if you haven't already. Just recently, I was having symptoms that sound sort of like yours (although I also had the battery light come on, which you didn't mention). Turned out the alternator was going bad, and wasn't putting out enough juice. I replaced the brush ($13 shipped), and it's running fine now.

[Dr. Shuffles]

And before replacing the switch, I would at least test it. 5 minutes with a multimeter might save you 30 bucks.

[xkjnboix]

Things I've done:
Clean IACV, FITV, TB
Replaced o2 Sensor, but it is a universal one.
Alternator
Checked and cleaned every ground I could find, I bet I missed one
Replaced coolant

good point Dr.Shuffles but i would take it from the OP's 1st post that it alt is fairly new ( no sarcasm intended )

[Rylan]

I had a problem sorta like this on a 89 f-150. When u unplug the iavc did u make sure u unpluged the neg side of the bat because it has to learn to idle again

[Dr. Shuffles]

good point Dr.Shuffles but i would take it from the OP's 1st post that it alt is fairly new ( no sarcasm intended )

Sorry, I totally missed that.

[xkjnboix]

Ive made that mistake before =P of course it was followed by * face palm*

[curtie94]

yes I did make sure to let the ecu relearn. I was even wondering if the base idle is too low causing the iacv to over compensate. When I unplug the Iacv the car stalls, but if I start the car with it I can keep it stays running, but really really rough.

The only thing is I have tried to adjust the idle, but the screw won't budge.

How about the EGR, I have never cleaned them.