wierd idle after a load.

[ryanapfel]

Got my bronco running real good except when i put a heavy load on the engine it has a wierd idle and sometimes dies. For example. I live up a pretty steep mountain road. When i get all the way up it and into my driveway it will fluctuate from about 400-1000 rpms for about 30 seconds untill it evens itself out and idles normally at a out 700-800. Its even more dramatoc when im 4x4ing and really cranking on it getting up a steep hill. As soon as i get to the top of the hill and let off gas it will die. It starts right back up everytime. Somtimes it goes back to the fluctuating rpms and somtimes it goes back to normal idleing. Any ideas? Thanks

 

[Krafty]

did you get all your vacuum leaks fixed?

 

[Bully Bob]

1) "...took it back to that hill and ran it in 4hi"

2) "Its even more dramatic when im 4x4ing and really cranking on it getting up a steep hill."

3) "..running real good except when i put a heavy load on the engine"

Here again, as I mentioned, IMHO, Ryan.. this is all wrong.. /emoticons/[email protected] 2x" width="20" height="20" />

Engines aren't happy with a "load"., or in your case, lugging it down. [-X (This strains the whole drive train & can break things)

You should be using 4x4 low range climbing hills & a gear that req. no more than 1/2 throttle.

As for the idle/tune....stick with M5...he will walk you thru... /

 

[ryanapfel]

Who said I was in 4hi when I was 4x4ing? Its not like I'm cranking it to 6 grand. I'm driving it normal. But to get up the mountain to my house I have it steady at about 3000. Regardless of how much I put my foot down it should die when I let off. Btw yes I re tubed my entire vacuum system.

 

[ryanapfel]

Also one thing I was thinking was one of my headers broke one of the studs off that bolt the exhaust on. So I only have the exhaust bolted onto the one remaining stud. Its pretty loud and obviously leaking. Could I be having a back pressure problem

 

[Bully Bob]

"Who said I was in 4hi when I was 4x4ing?"

YOU did..., that's why I copy/pasted your statment..!!!

(I want what you're having...! :lol: )

"Could I be having a back pressure problem?"

NO., not to any extent.

Pull it off, repl. stud & re-mount. Likely need a new gasket via runn'n it like that... [-X

 

[ryanapfel]

Yes. On a different post to show I fixed my previous problem. Dont take words out of context. I asked for help with a problem. Not a lecture on how to drive

 

[Bully Bob]

You got it..... "over-n-out" 10-7

Good luck...

 

[Krafty]

did you look at your throttle position sensor or idle air controller? the IAC has a tenancy to get stuck and/or not function properly when it gets a few airfulls of debris especially if you like to get down and dirty. I would recommend pulling it off and letting it soak in some carb cleaner before giving it a once over with a toothbrush then it should be good as new.

 

[ryanapfel]

Thanks Kraft I'll give that a try