Slow To Return To Idle - TPS?

[Tanman]

I have a 2005 Polaris 900 RMK "POS" Edition : D
I did the .710 v baseline TPS setting and .930 idle after startup idles really high at proper TPS setting. after lowering idle screw the sled idles at .780 v, but it is very slow to return to idle after revving up. The reverse works, TPS seems to act normally when plugged into my Digital Wrench. I did a yellow reflash matching the injector color and it seemed to run better. I unplugged the chassis relay and nothing changed. There is a good 60 PSI fuel pressure.
Engine was just rebuilt, new crank update kit, new seals, good pistons. Nothing was tampered with on rebuild, now something is wrong. sled ran fine before. Let me know what you think - Tanner

 

[cascadesnowjunky]

Possible vacuum leak causing a lean condition, check throttle body boots and everything that seals ( gaskets etc.).

 

[guidoxpress]

they have a slight delay in returning to idle after being reved...but if it takes longer then normal, i would suspect an air leak as well...crank seals, throttle body boots, throttle plates hangin up from gunk on linkage or the plates themselves..

 

[Tanman]

ok well I will check for leaks I suppose, I don't really wanna pull this motor back out but an air leak causing a lean condition did cross my mind. Thank you for you input

 

[guidoxpress]

before you get too carried away...

how long does it take to return to idle...2, 3 seconds i would guess is pretty normal..

there is an aerosal spray you can spray on the boots and crank seal and if it stalls the engine, you know where the leak is...but i am brain farting what it was that was safe to use....(also must be safe for rubber seals so it doesnt dry them out)??

 

[markoo]

Are you running it with the belt on or not. I found that with out the belt the engine would freewheel longer. with the track turning it would bring the rpms down quicker.

 

[Tanman]

It takes about 5 seconds to idle down completely, and the belt is on. I was told to use starting fluid on boots and seals to check for leaks. I was going to try that, or maybe block some ports off and do a cylinder leak down test.. : ( what a blast

 

[05900]

May want to check cables for adjustment,sticking as well as throttle block switches.