OK, here's the deal. it was the coldest its been here this year this morning, -4 deg. F at our house. Got in the truck to go to work, cranked 'er over and it caught but didn't stay running. Cranked again, same thing. Then I gave it about 1/4 throttle and cranked again and it started. I started letting off the gas and she idled down to about 500 RPM and started sputtering like it was going to die. I think I was even giving it a little gas still. I gave it more throttle, to about 1500RPM for about a minute or so (near where it normally would have been at these temps) then slowly let off and she was idling normally for that run time and outside temp, around 1000-1100RPM. Off I went to work. At lunch & after work, all normal.

From reading here, it sounds like the IAC is dirty or bad. Is this the beginning indication of a bad IAC? Or something else? If its the IAC, what's the best cleaner for it?

Motorcraft plugs & Global COPS have about 300 miles on them and she runs sweet...except for this. Gonna be cold here again tonight so I'm expecting a repeat performance in the AM.

Thanks for all the help!

EDIT: Y2K 5.4 w/ 149.5K mi.

 

If you determine your problem to be the IAC just buy a new one. I started cleaning mine and it worked, but I found it needed cleaning more than I cared to do the work. I first replaced the old with a new KEM part. That lasted about a year, or less. I finally bought a Standard and haven't had a problem since.

 

What motor?

 

Sorry, sig isn't showing up for some reason, Y2K 5.4 w/ 149.5K mi.

Show sig is checked in my profile, how do I get it back???

 

Well , right now you PCV line is sucking a little more moisture threw it than usual because it's so damn cold out their.

Moisture is getting in the IAC and freezing. If you notice on the 5.4's and most 4.6's the PCV line plugs into the manifold port back by the firewall, close to the IAC. You can pop the PCV hose off the valve and shoot a couple shots of Deep Creep into the line to help with that temporarily.

OR , pull the PCV system off the truck along with the IAC and clean it all up.

Clean the bottom of your oil filler cap. Clean the neck going into the valve cover as well.

That "Deep Creep" is perfect for the IAC . It a cleaner /lubricant that won't damage the sensor.


BTW - After each reply, before submit, scroll down to the bottom of the page and "check" the box that says "Show your Sig" - You have to do that each time you want to show it.

The box your referring to as "already checked ,show sig " is for PM mailings.

 

Mine did the same thing here yesterday also as stated in another post. It was -2 here. Except I have it happen two different ways. Yesterday I started it in the morning and let it warm up for 15 minutes. I'm driving and come up to a light. The idle is horrible. Wants to die. Give it gas to keep running and by the next light it goes away. It seems to always be at the same light when it does happen. Might be the open/closed loop change over. Then after sitting in the cold all day it did what you said yours did. It actually died on the first start then I had to keep the idle high to keep it running. After about 30 secs in smoothed out.

 

My 96 does it only in the neg numbers temp. Jam the snow brush in the seat and gass pedal go in for another coffee....

I've cleaned the IAC and thottle body it's better but still on realy cold days it will stall.

44

 

Thanks jbrew, I'll give 'er a shot. Autozone or Murrays for Deep Creep? I'm going to have to live with it until next week...goin' up to 'da UP to ride sleds & ingest antifreeze tomorrow. The good news is its warmer up there than its been here.

I might have tested your theory on that today though...today I made a 450 mile round trip to Fort Wayne. I would think that would dissipate any moisture in there, wouldn't you? We'll see in the wee hours...leaving at 3:00AM. I'll post back how it starts tomorrow when I get back.

 

Auto Zone carries Deep Creep

It's not a theory lol - I've had this truck since 98 .. It can get real bad if you take allot of short trips when it's cold out their. If not, it will still build up in the valve and the line though the winter months.

Just pull the PCV line and blow it out . You'll see the white sludge in their from moisture/oil mixing together. That sh^t makes it all the way into the intake if you let it.

Before a trip like that , I would blow out the line , clean the oil filler cap and wipe out the neck on the valve cover, coat the inside of the line with Deep Creep, Clean the PCV valve, reinstall the line and valve - fire it up. Rev it up a few times , then shut her down - your good to go.

Good Luck

 

I am having a very similar problem, I just haven't got the chance to pull out my IAC and have it cleaned. Would you guys recommend any brand of TB cleaner or what should be used to clean the IAC?

 

Well, sorry for the late follow up, but I got it fixed...I got a can of Deep Creep and cleaned up the IAC. Been workin' great for the last few weeks now.

I never got to test it yet in below zero temps like when it first started acting up, but I did at 6 deg. F and all's well.

I didn't have the white goop buildup in my oil filler neck or cap but maybe that was because I just came back from 2x550 mile back to back trips with it and the moisture evaporated out of there.

It probably wasn't helping any that my thermostat was bad either (it was opening at 170 and closing at 130 by our candy thermometer in the H2O test)...that's now also fixed and I regained about 1.5-2 MPG as a result of a combination of that and cleaning my MAF.

Thanks JBREW!

 

Wondered what happen to yuh - Is it finally thawing out over their

Glad you gotter runnin good again - I know the feeling after it hasn't run well for awhile.



Clarkston! That's about 20 minutes from here lol. It must be 40 out there today - It's been 50 the last couple days, first nice break we've had with the weather.