ok so i replaced my iac like a week ago. cleaned my maf. cleaned my tb. and i have reset it multiple times to relearn the idle and it still idles around 1100. my tps screw is all the way unscrewed cause even after i set it up right with a voltage meter and reset it and did the idle relearn steps it then idled at about 1800. i have a restrector plate because when i have the regular gasket on the iac it hangs rpms really bad and when i would go to stop it would rev to live 3000+ and then slowly go back down over the time period of like a minute. if u dont know what a restrictor plate it read these. someone please help me figure out whats wrong or i dont know if i want to keep the truck.....or at least go to an auto

http://www.therangerstation.com/foru...stricter+plate

http://mach1registry.org/forums/showthread.php?t=18330

http://www.rangerpowersports.com/for...d.php?t=229423

http://www.therangerstation.com/foru...ad.php?t=28608

 

What happens when you inplug the IAC all together? Do the RPM's drop off then?

Also have you set the TPS voltage?

 

if i unplug the iac, or the tps it does nothing...also i have a knn oil filter and i read somewhere that they can cause throttle sticking...is this true. my butterfly moves fine and the cable is not hanging up or any thing either.but i have noticed that with the tps screw un screwed the butterfly can get tight and kinda jammed in the tb and the peddle kinda sticks and i have to push it down kinda hard to unstick it and then i can use it normal. (not as bad as this makes it sound)

 

On the 99 I replaced my IAC but I still get the light for it constantly!

 

What a coincidence.

I made a new IAC gasket over the weekend, with smaller holes. I did not let it re-learn the idle but I did reset the PCM (and lost all my radio presets, dang it). I've only driven it to the post office yesterday and to work this morning.

I LIKE the way the rpms drop while shifting now. It reall helps my no-clutch shifting technique, allowing me to snick it into gear a few milliseconds earlier. I did notice that my idle is higher, but I attribute that to not allowing it to relearn yet. I'm just gonna drive it. When I parked it at work this morning (fully warmed up), it was idling right @ 1000, which is high for mine.

I'll throw the Scanguage back on it this week and see what the real idle numbers are. I lent it to my buddy so he could watch his wideband Air/Fuel sensor (CA O2) fail. It's been hard to convince him that the Bank1 WB A/F sensor heater (open circuit) is making his Forerunner run so poorly, lol.

Anyway, it sounds like you have a vaccum leak. Nothing else will make it idle that high. Put your TPS back to .96v and start looking at all your vaccum stuff. Pinch off the brake booster tube, unplug and cap your heater vaccum reservoir tube, find the EGR solenoid tube, cap it, look real hard at your PCV line to the air intake, etc. Might even spray some carb cleaner around and see if that locates a vaccum leak. Just be careful, it's flammable.

I cleaned my IAC, throttle body (removed it to do so), intake tube, etc, trying to cure a whistle sound that bugs me at 1200-1500 rpm. So far, it's gone. I'm sure it was coming from that little vent cap on the IAC.

When you installed the AVM hubs, what did you do to the vaccum tubing? That could be your vaccum leak, making the idle high.....

 

ya i took off my tb and my maf to clean them and on my avm hubs i caped the lines. ill try spraying the carb cleaner everywhere and see if it stalls. so if i put my tps back to .96 volts and it idles at about 1800 then i must have a vacume leak. i dont understand how turning the screw shouldnt change the idle cause it directly effects the butterfly. and i have that whistleing sound comming from the iac cap also.

 

how do you reset the pcm? how do you change the tps?

 

ok so i couldnt find a vacuume leak. i sprayed carb cleaner every where and nothing happened. i am concerned that when i unplug my iac nothing happens. do u think that my new one went bad already? it does kick down and when im rolin into a stop im at like 2000 rolling and when ii stop it goes down to like 1500 and i have to sit for like 10 seconds for it to go down to 1100 (with tps all the way unscrewed)

and to reset the pcm unplug ur battery for like 5 mins and the tps screw is on the side of the throttle body.

 

also if i unplug a vacume line (one of the little ones by the intake) the motor doesnt change at all. but if i unplug the big one at the brake booster it will stall. if i only let a little bit of air through the one at the brake booster it will drop idle. so why would a vacume leak cause a high idle and also why does it not do any thing when i unplug the little ones?

 

im thinking about just taking it to the ford dealer and spending the $100 bucks and know exactly whats wrong....what do u guys think?

 

found in the first kink hope it helps....

Okay, so I spoke to one of the largest dealers in the area today. They said that the trucks do have heavy flywheels (I had it backwards earlier) so that newbies don't stall the truck, which in turn makes the truck hold its RPMs longer. He said that this is a common complaint with the 2.3L 5-speed and that the issue has gotten better with newer Rangers like mine. He also said that Ford makes or made a lightweight racing flywheel that you can install that will drop the RPMs much faster after engaging the clutch. Also, other aftermarket parts manufacturers were said to make lighter flywheels for Rangers that will alleviate the issue. Honestly, I am not surprised Ford designed it's manual transmission for newbies. Hardly any Americans know what to do with a stick shift these days, it's sad.

Personally, I am not going to mess with my new truck at all until the warranty expires, then I might ditch the seats and replace the flywheel with a lightweight unit to speed up shifting. In the meantime, I'll be shifting like gramps so as to not excessively wear the tranny or the clutch. All in all, I still absolutely love my new Ford Ranger! And when I hit 60,000 miles, I'm going to love it just that much more. I am definitely a proud Ford owner.

 

i already solved the hanging rpms and now im worried abou the high idle...i think im just gonna take it into ford

 

atleast one thing is solved...good luck

 

High Idle... hmmm sounds familiar. I just had this same issue this past weekend because my mechanic put my IAC on backwards and it caused my RPM's to chill at 3,000 while Idling...

Check and make sure it's not backwards...

 

u mean like the cylinder part is facing the cab?

 

My IAC would be hard to install backward (connector pointing to cab) because the harness would be banjo-strung.

When I "touched it", I didn't have a problem with its idle. I still don't have a problem, but the idle is different with a smaller hole in the IAC gasket. Idle rpm is higher, ~1100 for about 3 seconds after a full stop, then drops to 850 or so (still no ScanguageII). I did the idle re-learn last evening after I enlarged the inlet side gasket hole to original size. IAC outlet to TB hole is ~1/2 of original size.

RPMs don't hang between shifts but @ idle in 3rd gear is pushing me @18 mph, which is unacceptable for my normal parking lot speed. I can't live with that so I'm putting the original gasket back on tonight. Another idle re-learn and back to "normal" for me.

Observations that mimic yours:

I pulled and thumb capped every vaccum line, PCV, EGR, EVAP, HVAC and BB. The BB was the ONLY one I could remove to affect the idle. It will sputter and hunt, then stabilize with BB disconnected. It does not stall but almost. Even repeated thumb plug rapid releases won't stall it. All those other vaccum lines, pcv, and even removing the oil cap had absolutely no effect, nary a stumble. This was all done fully warmed up with a steady 800ish idle.

I'm tempted to drive it with IAC disconnected just for symptoms collection, then vary the gasket hole sizes for a few days . If I could make it:

immediately drop rpms (without disconnecting the rear axle speed sensor-which works btw) for REAL engine braking

and drop idle to 800 well before coming to a stop (rear axle sensor does this too) AND keep the speedometer/cruise, I would.

I'm sorely tempted to put in a switch interrupting Pin 58 at the PCM (GY/BK wire VSS Input) to see how that works. I just hate to cut a wire for experimentation.

Hi Rob.

 

How's it going Earl

 

well i just dropped it off at ford with the normal iac gasket and and tps set to .96 volts (it was about 2 full turns from not touching the throttle...seems like a lot not sure if every body elses it that much.) but when i brought it in it was idleing about 1500 with the iac unpluged (had to to drive it there) and about 3000 with it pluged it (on start up i only ran it for about 5 seconds like that so i dont know it it was gonna goe down or not)....does that mean my iac is bad? id be PISSED if i have to pay them $140 to tell me that my new iac was actually bad! which is why i ruled it out since it WAS brand new. any way hope it runs like new when i get it back.

 

o and also with the restrector plate when i let of the gas it slowes down and will stall if i dont do any thing...and with the normal gasket it will keep me going and even speed me up so we are like opposite. earl

 

vacuum leak? idk much about the 3.0 but i had something like that it was the upper intake manifold gasket but idk if that would be your problem its worth a try

 

ya i tried all the vacuum lines and i found nothing.....im just tired of f****** with it

 

just let the stealership try i guess :(

 

I ditched that IAC gasket last night and went back to normal.
I did another idle relearn WITHOUT a PCM reset and it is back to normal today.

To recap, with a smaller hole IAC gasket:
higher idle rpm ~900
rpm drops between shifts
idle rpm hangs ~3 seconds @1100 @ complete stop, then drops to ~900

Back to stock:
normal idle
rpm hangs between shifts
idle drops to ~800ish as soon as I stop, hangs @ ~1000 if rolling

I've half convinced myself to cut that wire over the weekend, and add a switch.

Sorry to hear that you resorted to the dealer. Backyard quarterbacking wants me to say MAF. K&N filters use oil which contaminates the MAF (and dirties the IAC prematurely). We should have recommended you put a paper filter in there for a sanity check. At the very least, disconnect the MAF so the PCM uses its default values (see if it runs better disconnected, they sometimes do).

Please update this thread when you find out what they fixed!

 

when i unplug my maf it starts to stall and maby does (i plugged it back it before so) also i just cleaned every thing like i said in the first post. but i will definably let u guys know whats up.

 

keep us posted this seems like a crazy problem. but even crazier it probably has a super simple fix.