Idle issue, with no codes. Help please

[evadsec]

I recently just bought this 1997 Ford Explorer 2 door Sport Trac 4.0 liter SOHC, when I start the vehicle in the morning cold start it's like it's hunting for the position were supposed to be idling at it'll do it probably four or five times and then finally find the spot where it's supposed to be. Then it'll be fine until I warm the engine out and then sometimes if it's acting right it'll idle perfect at 650 or 700 and then it'll drop to five so I put it in drive and I can drive it just fine as long as I'm holding the gas pedal if I sit too long at idle eventually it will stall out, I've also had it died at a light not an exit ramp though, I've read the forums Googled a lot of things I took the IAC off cleaned it thoroughly it was really dirty I took them MAF off cleaned it thoroughly I also clean the throttle plate there's still a little bit of Gunk around the edge of the plate that needs to be kind of scraped off instead of wiped off that I couldn't get it does run better after the cleaning and I reset the computer by unhooking the negative wire on the battery terminal and then I ran alligator clip from the positive to that disconnected negative and let it sit for 10 to 15 minutes. It only does this sometimes not every time and I do not get any check engine light none no lean codes no codes at all I checked all the vacuum hoses they all look in good condition the only thing I have not done is actually remove the PCV valve and check it but it is plastic and it does look original. Without any codes though I have no idea what it is. Somewhere I read that the idle air control valve if it goes out we're starting to go out it will not produce a code I just want to double-check I have a meter I'm thinking about testing the throttle position sensor cleaning the rest of the gunk off the plate and maybe hitting it with some seafoam I don't know what else to do and this is really important it idles better when the heater is off once I turn the heater on I get a clicking noise it'll click one time and the RPMs fluctuate and then it'll set in it'll click every time while the rpm is hunting. It doesn't do that all the time either but while I was hunting with the heater on it'll only hunt from at idle in park from like 5 400 2 650 or 7 but it will pulse it pulsates.

 

[J_C]

When my IAC got dirty it would cause the engine RPM to drop when the A/C compressor kicked on. It did not set any OBDII codes at that point. I not only cleaned it but also propped it up on end and let a drop of light oil run down into the shaft bushing, moving the shaft up and down a few times to work it in then let it sit propped up to soak in for a few hours before reinstalling it.

It could be that yours is too worn and that won't work or that it only helps for a while, but a drop of oil... no cost, worth a try, and if it helps then gets worse again later, it seems a fair sign that you need a new IAC.

I doubt that it's your throttle position sensor or remaining gunk on the throttle plate.

 

[evadsec]

When my IAC got dirty it would cause the engine RPM to drop when the A/C compressor kicked on. It did not set any OBDII codes at that point. I not only cleaned it but also propped it up on end and let a drop of light oil run down into the shaft bushing, moving the shaft up and down a few times to work it in then let it sit propped up to soak in for a few hours before reinstalling it.

It could be that yours is too worn and that won't work or that it only helps for a while, but a drop of oil... no cost, worth a try, and if it helps then gets worse again later, it seems a fair sign that you need a new IAC.

I doubt that it's your throttle position sensor or remaining gunk on the throttle plate.

Yeah I think you're right cuz It All Leads back it keeps leading me back everything I do keeps going back to the idle air control valve the spring inside of it and some places were hard to get to with a Q-tip I used a Q-tip and throttle body cleaner And I never once I sprayed the inside where the spring is and then I'll do use Q-tips to get all the carbon out even still though when I took it off it had no gasket so I went and bought a new gasket it was only a dollar and then once you know while I was cleaning it the spring is actually like the carbon on the spring was so hard it was like I have I had to chip It Off if I took the Q-tip and and ripped off the cotton I used the plastic part or the wood part of the Q-tip to try to chip it free and I got some of it free but the remainder of the IAC was clean and I didn't let know I never tipped it upside down to where the motor was on the bottom but it seems like sometimes if I leave the cover off the engine and I tap on it before I start it I just take my lighter out of my pocket or something right I just tap the motor and then I tap the other side a little bit it seems like it does run a little bit better but when I went to put it back on and I look down and to the two holes of the intake there's a bunch of carbon in there too and I'm trying to figure out how to get to it clean it that's why I was thinking seafoam

 

[evadsec]

When my IAC got dirty it would cause the engine RPM to drop when the A/C compressor kicked on. It did not set any OBDII codes at that point. I not only cleaned it but also propped it up on end and let a drop of light oil run down into the shaft bushing, moving the shaft up and down a few times to work it in then let it sit propped up to soak in for a few hours before reinstalling it.

It could be that yours is too worn and that won't work or that it only helps for a while, but a drop of oil... no cost, worth a try, and if it helps then gets worse again later, it seems a fair sign that you need a new IAC.

I doubt that it's your throttle position sensor or remaining gunk on the throttle plate.

And thank you for your advice I'm about to take the IAC back off I'm going to clean it again and I'mma put oil and when you say shaft you mean the shaft where the Springs at Wright and keep the motor end up or actually keep the motor and down when you drop oil on it

 

[J_C]

When you look into the bottom hole of the IAC, on the solenoid end, the shaft inside that connects to the solenoid goes through a bushing. Put a drop of oil there, where the arrow points on the following pic, then take a pointed object and move the shaft up and down to work the oil into the bushing, holding the IAC as shown so gravity makes the oil run down into it. Let it sit like that for a while before reinstalling it.

Note that I just used a random picture of a similar IAC, yours will look a little different. I don't recall what I used to clean mine but there wasn't much carbon left behind. It was probably carb cleaner. If you need to get gunk off the spring then I'd try using something pointed and metal like an ice pick, x-acto knife blade, etc. but I wouldn't worry about getting the spring perfectly clean as long as it doesn't seem to be interfering with the shaft fully moving.

More important might be that hat-structure on the shaft that makes a seal against the inside of the IAC, in the partition between the two visible outer holes. Try to clean off where the hat contacts that area. You may need to push the shaft to get clearance to do that.

 

[evadsec]

When you look into the bottom hole of the IAC, on the solenoid end, the shaft inside that connects to the solenoid goes through a bushing. Put a drop of oil there, where the arrow points on the following pic, then take a pointed object and move the shaft up and down to work the oil into the bushing, holding the IAC as shown so gravity makes the oil run down into it. Let it sit like that for a while before reinstalling it.

Note that I just used a random picture of a similar IAC, yours will look a little different. I don't recall what I used to clean mine but there wasn't much carbon left behind. It was probably carb cleaner. If you need to get gunk off the spring then I'd try using something pointed and metal like an ice pick, x-acto knife blade, etc. but I wouldn't worry about getting the spring perfectly clean as long as it doesn't seem to be interfering with the shaft fully moving.

More important might be that hat-structure on the shaft that makes a seal against the inside of the IAC, in the partition between the two visible outer holes. Try to clean off where the hat contacts that area. You may need to push the shaft to get clearance to do that.

View attachment 152046

And that exactly what I'm getting ready to do ... I have throttle body cleaner CRC have WD-40 engine oil though I don't have any I just did an oil change my truck holds oil very well I'm really impressed with the Ford engine that's in it it doesn't burn it it doesn't leak it it stays full no matter how long on the highway 70 miles an hour with cruise control set I'm impressed with the motor, 147,000 miles.

 

[evadsec]

I'm about to go take the IAC off right now I will post pics here in a second.

Edit: also since I've had it which is only been like 3 weeks I noticed that the belt was dry rotted and crack so I immediately replace the belt got rid of the squeaking noise and I also replaced bought a brand new air filter there are no modifications and I will not buy a K n N filter, all stock.

 

[J_C]

WD-40 is not a lubricant. If you have nothing else, get a drop of oil off your engine dipstick.

 

[evadsec]

WD-40 is not a lubricant. If you have nothing else, get a couple drops of oil off your engine dipstick.

Ok that's what I will do. Dipstick.

 

[evadsec]

I got it off here's the pics I'm about to drop a drip or two of oil on it work it down into that bushing

 

[J_C]

Don't forget to take that black plastic cap off and rinse out the felt pads and the port going into it. Mine had two felt pads, I don't know if that's normal or not.

Supposedly some don't even have that little capped port but I figure that if it's there, it must serve some purpose.

 

[evadsec]

Don't forget to take that black plastic cap off and rinse out the felt pads and the port going into it. Mine had two, I don't know if that's normal or not. Supposedly some don't even have the plastic cap or felt filters but I figure that if they're there, they must serve some purpose.

I have no idea why that cap is on there either it turns though, I'm scared to take it off and then when I look inside it doesn't look like it goes to anything, but you're saying just pull it off and clean it ??

 

[evadsec]

Don't forget to take that black plastic cap off and rinse out the felt pads and the port going into it. Mine had two felt pads, I don't know if that's normal or not.

Supposedly some don't even have that little capped port but I figure that if it's there, it must serve some purpose.

I couldn't get I couldn't get the black cap off and I pulled pretty hard and it'll turn clockwise and counterclockwise but I can't just pull it off it doesn't want to come on so I don't know I could force it off but then I'm afraid I might break it or something but I work the shaft real good I dropped oil down it one drop and it actually feels a lot better when I open and close the valve

 

[evadsec]

Don't forget to take that black plastic cap off and rinse out the felt pads and the port going into it. Mine had two felt pads, I don't know if that's normal or not.

Supposedly some don't even have that little capped port but I figure that if it's there, it must serve some purpose.

I couldn't get I couldn't get the black cap off and I pulled pretty hard and it'll turn clockwise and counterclockwise but I can't just pull it off it doesn't want to come on so I don't know I could force it off but then I'm afraid I might break it or something but I work the shaft real good I dropped oil down it one drop and it actually feels a lot better when I open and close the valve

Don't forget to take that black plastic cap off and rinse out the felt pads and the port going into it. Mine had two felt pads, I don't know if that's normal or not.

Supposedly some don't even have that little capped port but I figure that if it's there, it must serve some purpose.

I'm about to try the cold start I mean I started it and drove it around a little bit and then it seems to be idling a lot better A lot smoother but it came and go before the stalling in the rough idle so hopefully it stays the way it is this time but I can see a big difference and the smoothness of the idle and the RPM actually stays where it is and when I turn the heater on it stays where it's at it kind of jumps up a little bit maybe by like 50 rpm but then it settles right back but I'm going to try it on a cold cold start here in a little bit so like you said if it does it again on my again but when I get to spare $108 I'll buy a new one unless I can find a cheaper one I'll just go ahead and buy it

 

[evadsec]

Don't forget to take that black plastic cap off and rinse out the felt pads and the port going into it. Mine had two felt pads, I don't know if that's normal or not.

Supposedly some don't even have that little capped port but I figure that if it's there, it must serve some purpose.

So it came back you're right it only last a little while it's a little worse this time actually... I took it back off I just got done cleaning it again this time though I took the black cap off I couldn't get both pieces off of the valve but I did get both the filters out and I scraped all the crowd off of it went and bought some air duster since I don't have a air compressor try to blow out most of its crate most of it off the filters they were I don't see how anything got through those filters so hopefully I don't know why it's there but hopefully to make it run a little better today I plan on finding a junkyard and pulling an idle air control valve off of a nother Explorer... Here's a couple pics I'm about to put it all back together right now it's nice and cold on the starter I'm a make a video Post-it message see how it's running but as you can see those two filters or like layered so I kind of split the letters apart and blue in between them and try to get all the dust, grim, dirt out

 

[J_C]

The bottom plastic piece doesn't come off AFAIK, just the cap holding the filter pads on. I soaked the little filter pads in the same cleaner I used for the rest of the IAC.