Sludge

I have noticed that past weeks that when the truck is warmed and idling in park the rpms where in the 800-1000 range normal for my rig is 700-800 rpms and now tonite after sitting at a drive thru window waiting for my food the idle was around 1250 in park. I found a few possible answers while doing a search. But i want to pick the brains of the ppl here a little bit more.

AgRunner06

I just found 3 vacuum leaks that contributed to my high idle. Also try cleaning the throttle body.

Sludge

I cleaned the TB last month but i will try doing that again.Maybe a seafoam treatment is in order. As far as checking for vacuum leaks whats the best way to find them

superjoe83

spray carb cleaner or brake clean around all of the vacuum hoses, and if the idle changes, you have a leak in that vicinity
and i think there was a thread here a few days ago where a guys idle was doing similar stuff like yours and it turned out to be either a bad or misadjusted TPS, i cant remember which one

Bumpin' Yota

hmmm interesting....

I cleaned my throttle body very carefully with a rag sprayed with TB cleaner only...

My hot idle went from about 700 to about 900 rpm idle...Cold warm up idle is 1200-1300 as expected.

uxb101

mine was doing the same thing and i cleaned the tb with tb cleaner couple days later my tps was shot had to change it costed $200 Canadian so watch where you spray that cleaner ,ive heard people taking the tps off then cleaning the tb i will next time i clean mine

AgRunner06

How in the world did you get TB cleaner on the TPS?

In case you didn't know, the TPS is a PITA to adjust. It took me and another person to get mine right. Just leave it on there and watch were you spray.

uxb101

i got some of the tb cleaner in the tps im sure of it,also i went to replace the tps and both screws broke off inside the tb what a nitemare ,had to take off the tb and drill new holes after that i put hex screws in it incase i have to adjust it by the way my timing is at 10 how far advanced did you set yours?
i did the afm mod but i did not change my timing do you advance the timing after changing the afm?

Bumpin' Yota

Well 10 degrees BTDC is ok I think, a lot of people use 12 and run premium and gain a little boost in performance.

LOL.....If i remember correctly mine is sitting at 15 or 17 or some ungodly ammount of advance and I've never touched it....I'll probably back it off to about 12 when I do the timing belt/water pump/idler. No pinging oddly enough...