What would cause high idle?

[bboll]

Lookng for everyone's experences in touble shooting high idle problems. I've seen the topic mentioned in some other threads but no conclusive fix, seems to be a mix of issues.

My sled is idling at 2250 at start up and does't come back down. Here is the history of the sled and my trouble shooting. 700 dragon with silber non intercooled kit. Sled idled great 1700 at 8500' feet during a trip last year. Now, MN it is idling much higher, 2250. No change to the electronics / gauges ince then. But I'm running quite a bit of stuff.

Turbo oil pump
Stock Headlights
Dual koso egts
AEM AFR / boost combo gauge
Fuel controller
I always leave handwarmers off.

I took the headlights out, no change.
I unplugged the AFR & gauge, no change.
Had the TPS set by the dealer, no change. (they said the tps was way off)

Silber starting numbers in the fuel contoller. Fuel pressure at 40 psi.
Would lowering the fuel pressure lower the idle?
I'm going to put a switch on the AFR next. Let the sled warm up and then flip it on. Does anyone one know what kind of power each of these peices of electronics draw?
Maybe it isn't elecronics. The AFR is reading 14.3-14.6 a start up. Is it getting extra fuel at idle? Did the dealer set the TPS correctly?

Any ideas would be appreciated.

 

[bk720]

Pull both map sensor out. ( factory and silber sensor) check prongs for any sign of green on prongs or damaged wiring.

 

[EZmoney]

Did you try backing off the idle screw??

 

[friscospices.com]

mine did the same 2 yrs ago. ended up being the TPS

 

[bboll]

Does the silber kit have a MAP sensor? The factory MAP sensor is the bocsh sensor that go relocated to the electrical cover, right?

 

[bboll]

I haven't tried that yet. I will need to look on a diagram to see where the heck it is. Any advice on location, how much should it be turned and in which direction? Is it like a carb sled where it will change the idle right away?

 

[bboll]

Thanks Frisco. I should look back at those posts that show how to make a TPS sensor. Dealer charged $50 to set it.

I had the weld next to my blow off valve break last year so I was doing some wrenching down there, will bumping it cause it to be out of spec?

How do I know if the TPS needs to be replaced?

 

[EZmoney]

If its like our pros it should be on the right hand side of the throttle bodies. To go down 400 rpm I'd say about a half a turn.

 

[bk720]

The 3 bar blue map sensor is in your billet theottle body adapter

 

[adam5187]

Check the cable routing. I had the exact same machine and setup and maybe if you had it apart you got t caught somewhere. Just a suggestion

Sent from my Galaxy Nexus using Tapatalk 2

 

[ridgeclimber]

Cause of high idle.

I have a 08 800 dragon with the BD turbo kit. Everytime I had a high idle problem its been a vacuum leak at the blown throttle body boot. Are you having problems building high boost? You have to pull off the throttle bodies and the intake boot, it is cracked. Letting extra air into the engine when idling and not on boost. Get the backing plate now available to bolt over top of the boot, it helps to not blow them apart.

 

[bboll]

I have a 08 800 dragon with the BD turbo kit. Everytime I had a high idle problem its been a vacuum leak at the blown throttle body boot. Are you having problems building high boost? You have to pull off the throttle bodies and the intake boot, it is cracked. Letting extra air into the engine when idling and not on boost. Get the backing plate now available to bolt over top of the boot, it helps to not blow them apart.

Makes a lot of sense especially given that I had air box off last year (craked near BOV). It already has the billet throttle body that silber made. I can't test big boost right now, I'm at 1000' and 7 psi is even a little crazy. I suppose I should tear it apart and check for leaks. It will build 7-8 psi in a hurry so it can't be a big leak.