07 apex rpm's very low and stalls when warm on idle

[biffdotorg]

Idle knob was my next guess too. But I was unsure how much was too much. So this is good advice at 1.5 to 2 turns.

Mine will not stall if I come to a stop and feather the throttle just a bit. It's like it sets the idle and I can walk away from it just fine. If I roll to a stop, it will stall once it hits idle.

If I come into a stop super fast and brake to a stop, locking the track, I have had that engine stall before I come to a stop! That may be something else though.

All if this is while the engine is hot. But as the others say, it will start right back up, and idle fine. Or I can pull my little feather of the throttle trick, and get it to idle fine. I just cannot come off throttle and idle on it's own. Maybe that is some sort of TPS issue?

 

[TBay Sledhead]

There doesn't seem to be a part no. for the IAC assembly or the thermostatic devise in the end. Anyone have any incite?

 

[TBay Sledhead]

Just in-case anyone is wondering what is inside the IAC.

 

[tomanytoyz]

As tomanytoyz just posted, try the idle adjustment knob first to see if that makes any change.
I have a little different thought on what may be happening here, as I've seen it a few times before.

The 4cyl motors use a coolant operated valve that controls idle thermostatically, and the red light that was mentioned here in earlier posts doesn't actually control the idle, but rather indicates when the motor has reached a safe operating temp. The ecu also limits the ignition system to prevent over-revving until it's up to a safe temp, and oil has had sufficient time to circulate.

I'm 95% sure your issue is in the valve assembly. I've seen a few of them that over time get some corrosion in them, or have something blocking the air passages.

If you have access to a simple vacuum gauge, remove the headlight pod and bracket and carefully set aside while leaving everything plugged in, including the air temp sensor. You shouldn't need to remove the airbox for this.

The manual calls for a special synchronizing hose to connect to the vacuum gauge, but for the purposes of diagnostics, a single gauge will get the job done.
Start teh sled up and let is warm up to operating temp. This is where you should make sure you have tried the main idle screw first to be sure it doesn't stall on you. You don't have to rev it up or anything, just let it idle.
Located at the base of each injector is a small vacuum cap held in place with a clamp. Remove one cap at a time and install the gauge, noting the vacuum reading as accurately as you possibly can.
*You'll be looking for each cyl to have just over 8in Hg, or 8.0709in Hg to be exact*
There are 4 small slotted screws on the top of the valve assy that are numbered 2,3,4,5. Cyl 1 is #2, cyl 2 is #3, and so on. Start with cyl 1 ist and use that as your standard. If you see any of them that are more than .4in Hg different from your #1 cyl, slowly adjust that cyl to bring it within spec, and then rev the engine two or three times for less than a second each, and re-check the reading at idle.

My suspicion is that you may have something plugging one or more of the lines, causing it to starve for air at idle. You can also remove the individual larger air lines to each cyl and gently blow them out and check for any corrosion in the fitting. Most of these issues are caused by humidity in the off season during storage, and can usually be fixed with a little cleaning.
If that doesn't solve the problem, I would look further into the valve assembly itself, as corrosion on the coolant side could be causing the valve to stick one way or the other. It operates just like the normal thermostat, only it opens the air bleed circuit when its cold and slowly closes as it warms up. The ecu controlls the fuel proportionately to temp as well, so if the two aren't operating at the same pace/level, it'll cause issues as well.

Sorry for the long read, but The idle valve is subject to wear/age/deterioration just like a normal thermostat, and on sleds that are starting to get a bit older, should be considered when diagnosing issues like these.
Pm me if you need any further help, or if all the suggestions here aren't working for you. I have the manual on my computer at my shop where I usually post from, and am glad to help you through whatever you need.

Very nice nate007 ! so i had it half correct to the idle issue..i never think about going to the service manual which i do have.i try to do it the old way lol . i always start the sled up 1 a week throughout the year every year since i have owned it,i think this is why my sled runs sooo dang good! i hope he and others have this issue fixed with your help !

 

[WinderFab]

Nate007 thanks for your help, I'll give that a try and let you guys know how it goes, thanks again...

 

[vx700xtc]

so, what if you can not maintain idle for synch purpose?

 

[TBay Sledhead]

Well I just changed The IAC coolant end onto mine from a sled that is ok. Sled still idles down to 1,000 rpm and idle speed adjuster does nothing. Going riding tomorrow and will report back findings. Going to have to get a vac gauge and test.

 

[WinderFab]

Thanks TBay Sledhead for the update, please keep us posted if you find anything and I'll do the same,

Will any vacuum tester work?

 

[02xtreme]

Thanks TBay Sledhead for the update, please keep us posted if you find anything and I'll do the same,

Will any vacuum tester work?

I tried a vac tester from Cdn Tire and the ID for the hose that attaches to the throttle body was a bit too big. I zip tied it but still couldn't get it tight enough cause when I turned on the sled the gauge would just bounces all over. I couldn't find a hose with a small enough ID to fit the 4 brass nipples on the throttle bodies so kinda gave up on doing this test. It was also analog so hard to read the exact reading which seems like it could be critical for this test.

 

[TBay Sledhead]

Well I went out riding today and the idle is 90% better but still not quite right. Twice it tried to stall on me earlier in the day. Last half of the day it never acted up at all. Ran the sled hard through 3' of powder, what a blast. If I could get hold of a brand new one I think I would have it licked. I guess I'll have to give Port Yammy a call and see if it is available seeing as I can't find a part no. in any fiche for this part.

 

[WinderFab]

Tbay Sledhead you said that you installed one from a good working sled but yours wanted to stall but than ran fine,

If the sled it came off does not stall out on idle than why would yours want to stall out early in the day,

I'm not doubting you just trying to figure out this problem that we are having,

How bad was your sled before you did the swap? Mine will stall out every time once it's on idle for a few seconds,

My riding partners apex which has a few more km than mine runs good, doesn't not have this problem but he will not make me switch parts , I don't blame him, don't touch what ant broke he tells me lol...

Do you have any ideas why it wanted to stall but than ran fine?
Do you think running it hard in powder has anything to do with it?
Thanks

 

[WinderFab]

Tbay Sledhead I've been doing a lot of research on the IAC , IAC seems to be the problem when theres idling problems, a few guys also said that the carbs need to be synchronize, is that true? And did you do that to yours ?

 

[TBay Sledhead]

Tbay Sledhead you said that you installed one from a good working sled but yours wanted to stall but than ran fine,

If the sled it came off does not stall out on idle than why would yours want to stall out early in the day,

I'm not doubting you just trying to figure out this problem that we are having,

How bad was your sled before you did the swap? Mine will stall out every time once it's on idle for a few seconds,

My riding partners apex which has a few more km than mine runs good, doesn't not have this problem but he will not make me switch parts , I don't blame him, don't touch what ant broke he tells me lol...

Do you have any ideas why it wanted to stall but than ran fine?
Do you think running it hard in powder has anything to do with it?
Thanks

As to why the sled ran that way I don't know.

Sled was stalling all the time the last couple of days.

I don't think the powder running had anything to do with this issue. I've done that before with no issues.

I've installed my part on the other sled and will probably run it later today.

I've ruled out anything to do with the airbox temp sender as I've tried 2 different ones from sleds with no problems

 

[02xtreme]

Tbay Sledhead you said that you installed one from a good working sled but yours wanted to stall but than ran fine,

If the sled it came off does not stall out on idle than why would yours want to stall out early in the day,

I'm not doubting you just trying to figure out this problem that we are having,

How bad was your sled before you did the swap? Mine will stall out every time once it's on idle for a few seconds,

My riding partners apex which has a few more km than mine runs good, doesn't not have this problem but he will not make me switch parts , I don't blame him, don't touch what ant broke he tells me lol...

Do you have any ideas why it wanted to stall but than ran fine?
Do you think running it hard in powder has anything to do with it?
Thanks

As to why the sled ran that way I don't know.

Sled was stalling all the time the last couple of days.

I don't think the powder running had anything to do with this issue. I've done that before with no issues.

I've installed my part on the other sled and will probably run it later today.

I've ruled out anything to do with the airbox temp sender as I've tried 2 different ones from sleds with no problems

U da man!! Keep reporting back!!

 

[TBay Sledhead]

Never got to run the other sled today as I took the skid out to service it and noticed it needs a new track. So I don't think it will be run until I get that changed. My sled work just never seems to end.