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Discussion Starter #1
When my 98 Kia Sportage MT is in neutral and I am coasting the car idles rough as if it's about to stall. After I stop idles is smooth. When I disconnect the speed sensor the problem stops. This will happen if I am moving in neutral just slightly, like the coast to stop at a light (1mph). I have replaced MAF, IAC, Fuel Pump and fuel pr. Anybody seen this or know how to resolve?
 

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My 2001 5spd manual 4x4 sportage was doing something very similar. When rolling in neutral, the idle would always run high, around 1500rpm or so, until I made a complete stop, then it would settle down. Although it wasn't running rough, the solution to my problem was simply repairing a small vacuum leak. The vacuum line running the front hubs broke off the back of the manifold. Replaced the line and it now runs great again.
Check for vacuum leaks perhaps?

I believe what's happening is that the ECU sends a little extra fuel to the injectors when the vehicle is moving. This helps drive-ability when driving/idling in gear. But then again, I'm not a trained mechanic...
 

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2000 Kia Sportage EX, 2005 Volvo S60R
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i suspected something like this but i just didnt want to start relplacing vac hoses. lol guess ill have to though. thanks for chiming in arctic
 

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Discussion Starter #5
ECU for sure

I am not sure about vacuum leak but it is obvious from your post and mine that the ECU is doing something just because the wheels are moving. I am not sure why regular idle is not sufficient when the wheels are moving though. Any ideas? Thanks for the post!
 

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2000 Kia Sportage EX, 2005 Volvo S60R
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this is indeed the case. I have not solved this, or started looking for vaccuum leaks yet, been taking care of a few small other things. but I have noticed that it will idle high while rolling in neutral and will not drop down to proper idle until at a complete stop. and if im on a hill and let the vehicle start rolling from a stop, the idle will rise again. so what is the vehicle doing while the wheels are rolling if youre not in gear?
 

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1999 Sportage A/T 4WD
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988 Posts
Yes, you could check if your Sportage cam sensor has got its wires insulation damaged as the one shown in that post, and in case fix them.
 

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2000 Kia Sportage EX, 2005 Volvo S60R
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I will inspect them when I do my valve cover, but this symptom of high idle is ONLY when the wheels are rolling, in neutral so the engine is idling. When I come to a stop the idle settles down to normal, but if the wheels start rolling again, even without using the motor, just leaving the trans in neutral and let the vehicle start rolling down a hill and the idle will come up to around 1100-1200 rpms. Im not sure if a bad camshaft sensor problem would occur ONLY when the wheels are moving...
 

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Did you resolve this?

I am experiencing the exact same symptoms after changing the spark plugs. What did you do to fix this?
This is really frustrating just after replacing the heater core which was a total pain.

Thanks!
 

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2000 Kia Sportage EX, 2005 Volvo S60R
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no fix. no idea. almost seems like its in the computer. not a huge problem but it annoys the $h!t outta me. wheels are rolling, even in neutral = higher idle. but whyyyyy
 

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Caribou, Otter, Buffalo
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Have been ruminating on this all night...

Is this issue related to you applying the brake?

Have you monitored manifold vacuum during the situation??

Have you monitored the fuel/air ratio during these events??

During these events, what is the status and voltage on the B1S1?? (Lean/rich, switching/not)

.... Philip
 

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2000 Kia Sportage EX, 2005 Volvo S60R
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VSS = vehicle speed sensor? -- I havent checked

Issue does not change with braking. I can pop it out of gear and roll to a stop and the engine will idle high until the wheels stop rolling then it immediately drops to normal idle.

I have not monitored during high idle but I will and report back.
 

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'96 Camry v6 XLE, '00 Camry LE
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VSS = vehicle speed sensor? -- I havent checked

Issue does not change with braking. I can pop it out of gear and roll to a stop and the engine will idle high until the wheels stop rolling then it immediately drops to normal idle.

I have not monitored during high idle but I will and report back.
Hi Philip & tspot,

This behavior is normal - the ECM will send extra fuel and/or adjust the IAC valve, if it senses the vehicle is moving to keep idle up until the vehicle stops -> the ECM does not detect movement on the VSS sensor.

Both the Sportages here do the same thing - on mine (Fed. Emissons) idle is approx. 1,500 rolling in neutral until stop, the other (Cal. Emissions) is approx. 1,300 rolling in neutral until stop.

FYI & Regards,
Robert
 

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1998 Kia Sportage 2WD Base Model
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Hi Philip & tspot,

This behavior is normal - the ECM will send extra fuel and/or adjust the IAC valve, if it senses the vehicle is moving to keep idle up until the vehicle stops -> the ECM does not detect movement on the VSS sensor.

Both the Sportages here do the same thing - on mine (Fed. Emissons) idle is approx. 1,500 rolling in neutral until stop, the other (Cal. Emissions) is approx. 1,300 rolling in neutral until stop.

FYI & Regards,
Robert
Curious, I'm aware that the ECM will increase IAC position when it sees the TPS percentage increase in anticipation of a closed throttle event (to prevent a stall). I have never heard of any idle control system that increases simply due to vehicle movement. It appears to be intentional with the sportage but I have never encountered this on my own kia.
 

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'96 Camry v6 XLE, '00 Camry LE
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I think the reason the ECM commands fuel / higher idle when coasting in Neutral is to allow for a clutch start, with Key On, Engine Off, ie: 'popping the clutch' - (VSS related)

It could also be MAF related / ECM detecting airflow while coasting, that may be raising the RPMs -> commanding fuel with Key On, Engine On,

re: higher idle, given that both Sportages have the mechanical fan clutch removed & replaced w/ electric fan, that may account for (some of) the higher rpm observed here, I suspect..

When in gear, and coasting, the ECM does cut fuel to the injectors (via TPS) as expected,

Have noted this behavior on (3) different Sportages here, all 5 spd. manual, all 4x4.

Regards,
Robert
 

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2001 kia sportage
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Mine does this too!

Bump! old post -

Hey everybody, it's been awhile!
Back in the day I was registered here under a different name but had to re-register.

Anyway, yes, I'm still driving my good 'ol 2001 Kia Sportage which I bought new and have maintained myself. 300K+ miles.
I am not the original poster of this thread, but my car does the very same thing too.

It is not a normal condition, it started about a year ago and I've tried everything I can think of to diagnose it. Sure, the idle speed goes up a bit when the car rolls forward, but it's not supposed to go this high!

I've inspected for vacuum leaks, replaced the IAC, the PVC valve, cleaned the mass air sensor then replaced it, but put the original back in as the replacement made things worse.

This car has the mechanical clutch on the fan. Manual tranny. Base model, no AC or anything. It is a 4x4 but I blew the original hubs long ago and installed manual hubs, capping the vacuum line at the manifold.

I know it's old, but if possible I'd like to keep it on the road till the doors fall off! I can't afford a replacement.
Thanks in advance for any tips y'all might be able to provide.

I'm thinking - check the compression? can this simply be a symptom of a worn out engine?
I have not checked the coolant sensor or TPS, don't reckon they might cause this. Does kinda behave like a vacuum leak.
 
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