engine issue

[K3500]

soo ive noticed when i come to a red light my truck sometimes goes into a mode where it drops rpms' rapidly then raises up from 300 at its lowest to 800 highest. then sometimes when it goes into reverse and i have my foot on the break to look back it does it also. it drives smooth and idles fine at neutral and park.

does anyone have any ideas on this ??

 

[redneckchevy90]

maybe throttle position sensor going out.

 

[///RAGMC]

Check it for codes

 

[K3500]

theres no codes....i just read online that the throttle bodies biuld up junk inside them after a while and you should clean it to have a better idle. maybe this?

 

[kaboom187]

Hey i have a haynes mechanic book here and it says to simple get some TBC and clean out your throttle body. I dont know how its set on your truck but on my k2500 i just remove my Air cleaning system and then have acces to it. Hope this helps .

 

[K3500]

haha i completly forgot but the last owner of my truck threw in a haynes manual!! ill go check it out.....and tomro if it stops raining il try to clean it. i was thinking about trying that zmax stuff soo maybe tomro will be a little tune up day with a fresh oildchange and throttle body cleaning...

 

[STEBS]

so basicly ur truck has irratic idle when coming to a stop, and sometimes in reverse... is this right?

 

[kaboom187]

haha i completly forgot but the last owner of my truck threw in a haynes manual!! ill go check it out.....and tomro if it stops raining il try to clean it. i was thinking about trying that zmax stuff soo maybe tomro will be a little tune up day with a fresh oildchange and throttle body cleaning...

Yeah those books are really great for doing work your self !

 

[K3500]

Yes not all the time jus here nd there

 

[K3500]

i also noticed when going into work that when it happens...if i push down harder on the break it stops?