'00 V8 EB-Idle better when IAC UNplugged

[L2rocku2]

Hello All
As far back as I can remember, the idle has always seemed a bit high. Cold start up around 1500 +/- Warm idle 1000-1100 +/-

Bought her new for wife & it's been her daily driver since. I'm doing a complete tune up and remembered the high idle, so I took a closer look.

When engine is @ operating temp and you UNplug the IAC, shouldn't the engine run rough, if not stall?? When I unpug the IAC, idle drops down to 600-700 rpm's and runs smooth as silk :scratch:
Possible that the IAC needs to be cleaned/replaced??

Just turned 71,000 miles.Doing/done= Sea-foam, plugs, pvc, ALL coolant lines/hoses, cleaned maf & TB, vacuum hoses.

Any thoughts on this would be appreciated

 

[sethpdx]

Bump- did you resolve this? My :exporange has the same symptoms

 

[SoNic67]

Probably IAC is not closing properly, even at the lowest voltage send by PCM?

 

[pitbulldell]

Did you try turning that lil screw to back the Idle down with the IAC plugged in? Maybe someone before you cranked the idle up. I would clean the IAC, and the throttle body and plug the IAC back in and if the idle still high i would just back down the idle screw and see how it runs.

 

[SoNic67]

What idle screw? IAC does not have one.

 

[yavapaires]

If the engine idles down with the IAC unplugged, it ain't the idle screw causing the problem. The engine would NOT idle down if the screw is turned in.Makes no difference if the IAC is plugged in or not.

 

[pitbulldell]

What idle screw? IAC does not have one.

I was refering to the idle screw thats on the throttle body.

 

[SoNic67]

I don't have one.

 

[L2rocku2]

Bump- did you resolve this? My :exporange has the same symptoms

Hey Seth. After doing the seafoam, the idle came down and it didn't change rpm's whether it was plugged in or not. I had planned on checking it out further, but here's a glimps of what happened . . . .

I had everything planned out. Send (fly) the mrs & kids to her folks for 2 weeks (allowing me to work on her without being rushed or it needing to be driven the next day), all the parts had already arrived from rockauto, only a week to go before they leave and . . . . . BAM . . . radiator tank seal blows!!

This is what i did- new radiator, t-stat, EVERY hose under the hood, water pump, heater control valve, replaced both upper control arms (caster/camber bolt kits), getting her aligned, 5 shocks, oil & filters, plugs & all new seat covers.

 

[sethpdx]

Hey Seth. After doing the seafoam, the idle came down and it didn't change rpm's whether it was plugged in or not. I had planned on checking it out further, but here's a glimps of what happened . . . .

I had everything planned out. Send (fly) the mrs & kids to her folks for 2 weeks (allowing me to work on her without being rushed or it needing to be driven the next day), all the parts had already arrived from rockauto, only a week to go before they leave and . . . . . BAM . . . radiator tank seal blows!!

This is what i did- new radiator, t-stat, EVERY hose under the hood, water pump, heater control valve, replaced both upper control arms (caster/camber bolt kits), getting her aligned, 5 shocks, oil & filters, plugs & all new seat covers.

Wow, that sure is a lot of stuff you got done! oh and nice plan with the wife and kids

 

[L2rocku2]

Wow, that sure is a lot of stuff you got done! oh and nice plan with the wife and kids

Lol, Thanks. We only have 2 vehicles, the X & last dec I bought a new 2010 f-150 crewcab 4x4 lariat. Our 17yo daughter has basically taken over the X from mom and thinks of the x as her daily driver :shifty_ey LOL. So, there was no way that I was gonna work on her @ night (after my real job, and worry about having it drivable by morning. So pack them up & drop them off @ the airport

I rarely drive it, if at all, between oil changes. When I find some time (and it's actually home lol), i'll take another look and see if it still idles the same. If you find out why yours is idling high, please post it!!

 

[sethpdx]

Lol, Thanks. We only have 2 vehicles, the X & last dec I bought a new 2010 f-150 crewcab 4x4 lariat. Our 17yo daughter has basically taken over the X from mom and thinks of the x as her daily driver :shifty_ey LOL. So, there was no way that I was gonna work on her @ night (after my real job, and worry about having it drivable by morning. So pack them up & drop them off @ the airport

I rarely drive it, if at all, between oil changes. When I find some time (and it's actually home lol), i'll take another look and see if it still idles the same. If you find out why yours is idling high, please post it!!

OoOo the F-150s sure are nice! I've been looking to get in one as the rates and offers are out of this world right now (no way would I trade in the x). I'm going to start with cleaning the iac. If that doesn't work Ill get a new one (dont care for the moose call lol).

 

[L2rocku2]

The 150 is ok. I'm not nearly as impressed with it as I was when i ordered my 95 150 supercab, eb 4x4 off road. Listen, i drive like i stole it every time i'm behind the wheel (regardless of what i'm driving lol). I highly doubt their was another like it in the state!! EB, 4x4 off road, Posi BOTH front & rear, manual hubs, stabilizer bars front & rear, handling pkg, susp pkg (overload springs again, both front & rear), towing pkg. In 16 yrs she NEVER let me down!! Never had a flat or dead battery. Less than 1 month before i sold it, i changed the FIRST bulb to go out (third brake light). Hated to sell her, but it was a must. Anyways lol back to the post. I also cleaned the MAF & throttle body. Think i forgot to mention the PCM valve to my earlier list.

 

[L2rocku2]

Ooops that's PCV valve lol getting tired

 

[sethpdx]

The 150 is ok. I'm not nearly as impressed with it as I was when i ordered my 95 150 supercab, eb 4x4 off road. Listen, i drive like i stole it every time i'm behind the wheel (regardless of what i'm driving lol). I highly doubt their was another like it in the state!! EB, 4x4 off road, Posi BOTH front & rear, manual hubs, stabilizer bars front & rear, handling pkg, susp pkg (overload springs again, both front & rear), towing pkg. In 16 yrs she NEVER let me down!! Never had a flat or dead battery. Less than 1 month before i sold it, i changed the FIRST bulb to go out (third brake light). Hated to sell her, but it was a must. Anyways lol back to the post. I also cleaned the MAF & throttle body. Think i forgot to mention the PCM valve to my earlier list.

Lol nice! Shesh that's a hellava truck you used to drive.. Ford made that one on a monday for sure

So I cleaned my IAC with a whole can of electrical parts cleaner. I went to town spraying cleaner in every corner. It was 90 degrees today so it dried out within an hour or so.

Well I reinstalled the iac then reconnected the ground cable to the battery. Started up the x and what do you know.. it purred like a kitten at 750-800 rpm

 

[L2rocku2]

Nice job seth!! I did include a gasket for the IAC in my orders from rockauto, but didn't have the time to take it off & try cleaning it. If i find out that the idle is creeping up again, taking it off and cleaning it will be the first thing i do!!

Another tidbit about my 95 150. I had less than 8 wks before xmas & that truck, myself, mrs & our 3 month old daughter were going to be on the road from Phoenix, az to N/E Iowa. My previous 2 f-150 orders both took over 8 weeks. I found out when the ford sales rep would be at the dealership (3 days after i ordered) and went to see him.

I explained to him the time crunch, how the truck has EVERYTHING i want & that i wouldn't want to change a thing. So if there is any way that you could help get the truck built in time and maybe even done with a few days to spare, i would greatly appreciate it. Nobody's perfect & being able to drive her for a few days before heading out, just in case something needed fixed or adjusted, would be awesome. I can guarantee you, if i'm broke down, in winter, on a frozen & diserted highway with a wife and a newborn at xmas, aint NOBOBY gonna be happy no matter where you are!! He gave out a chuckle and a nod. He asked me to write down my name on his notepad and said he would do what he could. I thanked him and left. 2 WEEKS later the dealership called & asked me to come get my truck!!!!

 

[sethpdx]

Yes cleaning isn't that hard at all and is cheap Today it was 80d degrees out and I heard a very very quiet moose call (so quiet it was over shadowed by the power steering pump).

That dealer pulled through like a champ. It's nice when things come together like that.

 

[L2rocku2]

Yes cleaning isn't that hard at all and is cheap Today it was 80d degrees out and I heard a very very quiet moose call (so quiet it was over shadowed by the power steering pump).

That dealer pulled through like a champ. It's nice when things come together like that.

I'm puzzled over the "moose call" you hear?? I don't get up north much, or hunt, so i'm trying to imagine what sound your hearing. I'm assuming that it has something to do with the vent on the IAC? Interesting, can't say that i've ever heard that under my hood :shifty_ey


Oh, dealership didn't have nothing to do with getting the truck sooner, it was all do to the ford rep!

 

[sethpdx]

I'm puzzled over the "moose call" you hear?? I don't get up north much, or hunt, so i'm trying to imagine what sound your hearing. I'm assuming that it has something to do with the vent on the IAC? Interesting, can't say that i've ever heard that under my hood :shifty_ey


Oh, dealership didn't have nothing to do with getting the truck sooner, it was all do to the ford rep!

It is indeed a sound that develops from the vent (when it is above 80 degrees and humid in my expediences). Funny, I cant find the sound clip on youtube.. Maybe I'll have to shoot a video, assuming the IAC gets dirty again and makes that loud moose call. I tell my wife the x is whining.. I'm hot

Thats right the factory rep.. I could see how someone in that position could pull some strings :exporange

 

[L2rocku2]

It is indeed a sound that develops from the vent (when it is above 80 degrees and humid in my expediences). Funny, I cant find the sound clip on youtube.. Maybe I'll have to shoot a video, assuming the IAC gets dirty again and makes that loud moose call. I tell my wife the x is whining.. I'm hot

Thats right the factory rep.. I could see how someone in that position could pull some strings :exporange

At least you know what's causing it. If it were me, and it did come back, I'd just replace it & be done with it

Damn fine job seth!! Glad you came and posted