'06 Apex sometimes idles low...almost sputtering...

[rxrider]

Have you checked you C0 idle adjustment.
From what you said, whacking it open and let off it will drop idle to 1100 then recover. To me it sounds like a fat condition in the idle speed/slow cruise circuitry, can be adjusted by altering the C0 values.
If all other ideas don't work, check this one out.

With the pressure in the fuel rail I don't think it will gum up, if one or more injector is clogging up you will be running on 3 or less cylinders, that is very noticeable and I don't think your sled will idle at all.

 

[ZR800EFI]

It does recover usually, but not even right away. Sometimes it will idle low for a bit till I turn it off.

Yes, the last couple year I had the C0 settings at -5 across the 4 and it's been fine. Just this past weekend I set them back to stock, 0, and still had the same problem. I guess I could have went lower than -5 to try it, but not sure it would help.

 

[rxrider]

On turbo sleds we usually start out with C0 at -10 and fine tune from there. Give it a try.

 

[blue er]

had some sputtering last year, changed the plugs and cleaned out the throttle bodys with an old toothbrush and some intake cleaner, sprayed out all the breather hoses and idle controllers well. problem solved idles right at 1500 again

 

[ZR800EFI]

Double-checked boots, they seem fine.
Changed C0 settings to -10 then -15, still no better.
Changed plugs, and went back to new CR9EB. Still sputtering.

Haven't made it to a fuel filter yet...

Thanks for everything so far...Any other ideas before I go that route?

 

[vintage srx]

Check to see if you have a cracked exhaust or bad doughnuts.

 

[ZR800EFI]

Exhaust is fine...had it apart last weekend to check the donuts.

 

[obile]

turn your idle up a bit. 1450 to1500 any lower and it will tend to hunt a bit. had the same problem on mine was idling at 1250 to 1300 turned it to 1500 and havent had a problem since.

 

[ZR800EFI]

It does idle right at 1500 when running properly. Last year when it was stumbling, I turned the idle up and it was better at that point, but then the next time it was running fine, my idle was 1900...so too high. So I turned it back down.

Not a solution to the problem...just a bandaid...

 

[fisch137]

How big of a job is it to change a fuel filter on Apex/Attak? Anyone get into one yet??

 

[ZR800EFI]

I haven't yet...and don't know. I guess it 's in the tank.

I can't see that being the problem though...never know I guess.

 

[fisch137]

Can anyone tell me how often they change fuel filters? What is recommended and are people really doing?

 

[Iceman57]

Did you check the TPS adjustment yet? You can do it on the POD or adjust the sensor itself on the throttle body rail using a meter and adjusting the sensor until a certain voltage is obtained, I adjusted mine at the TPS. My sled acted exactly like what you described your sled doing. I re-seated the boots and adjusted the TPS and the problem is now gone. I know you checked your boots so I would check the TPS adjustment. I was told by my dealer that some of the sensors have been failing.

 

[sherlock29]

Iceman57,

do you have a step by step for doing this TPS check?

cheers!

 

[ROCKRTX]

Got the same problem on mine, CO set at 0.
What is the spec setting for TPS sensor at idle?