Idling Issues

[HemiBabe]

So here lately I have been noticing that when I have my AC on and it kicks on, the truck tries to die. It normally idles around 600-700 rpm and when it kicks on, it drops to 300 rpms and starts trying to choke itself out. Also when I go from drive to reverse, it does the exact same thing with or without the AC on...

Anyone know what it might be?

 

[05singlecabHEMI]

never had this problem with the AC on. but when my truck is cold and i go from reverse to drive if i wait to press the gas, itll die on me. never really found out what the problem is though... so i let it idle for a couple minutes before i switch gears. i still wanna know why it does this. lol

 

[KGBIGCOUNTRY]

Does the compressor make any odd sounds or notice a lack of performance from your A/C?

 

[tmerritt530]

Could be a dirty throttle body. Hows yours look? Might be time to clean!

 

[KGBIGCOUNTRY]

Had the TB recently or any of the ac lines off the truck?

 

[HemiBabe]

Hmm, the ac compressor makes a loud click noise when it comes on, the TB was put on like 6 months ago but I did the tps reset then.

 

[tmerritt530]

Have you tried another reset? Let the truck try to learn it all over

 

[TexasRammer]

not sure but maybe something with the throttle body, or tps. recently i had some really weird idling issues and it would also die if I went from park to reverse to fast after starting up. I replaced the tps and all was well. But im not sure why it would have anything to do with the AC, might be a different problem

 

[truckin151]

No codes?

 

[HemiBabe]

Nope no codes, I guess I can try to reset the tps and see.


[tapatalkin]

 

[Hammer_Z71]

Ground the throttle body, I bet the idle will smooth right out...

 

[HemiBabe]

How do you do that?


[tapatalkin]

 

[Hammer_Z71]

How do you do that?


[tapatalkin]

My idle has always been erratic as hell, can't really remember if it was when it was stock or started when I began modding the hell out of the truck in '05, but regardless it's been pretty bad for a long time. I can only really remember it stalling at a light maybe twice, but the needle will always jump and dip pretty low when sitting still. Not uncommon for the idle to drop to a point where the truck starts to shimmy a tad, like it does just before a stall, but then it almost always "catches itself" and the idle will bump up a tad and not stall. Have always cleaned the TB and PCV at 15k miles religiously, never helped the idle.

I grounded the throttle body a couple of months ago and the idle smoothed out instantly, stays pegged right at 700 rpm now, the needle sits so still you'd think I glued it in place, LOL.

Run you a wire (10 gauge or more, WalMart sells a nice 39" six gauge, pre-terminated, in the riding mower department for under $5), from one of the four bolts on the face of the throttle body to either the negative post on the battery or one of the chassis ground bolts.

 

[Deviate]

I'm on this like a BOSS! Mine has been acting like that lately but only when the truck is cold. Once it warms up it's fine. I have some extra wire here from an audio build I'm about to do. It darn sure can't hurt to try this.

My question is...where did you hear about this and what was someone doing to think they should ground the TB in the first place?

 

[Hammer_Z71]

I'm on this like a BOSS! Mine has been acting like that lately but only when the truck is cold. Once it warms up it's fine. I have some extra wire here from an audio build I'm about to do. It darn sure can't hurt to try this.

My question is...where did you hear about this and what was someone doing to think they should ground the TB in the first place?

It's actually a "trick" that started for better throttle response at the track when TBs started to be "fly-by-wire" and not using a traditional, manual throttle cable anymore.

There are some HUGE threads on other forums about this and I believe a pretty active discussion on the Diablo Tuner forum as well. There is a thread about it on this forum in the 4th Gen section.

The throttle motor is grounded but only with the tiny wire in the harness, but the actual throttle body is not and is connected to the manifold by a rubber boot, so no grounding. I measured impedance on my TB that fluctuated between 1.86 and 2.28 Ohms with my meter and then simply touched the grounding cable to it and chassis ground and watched it peg to zero.

The theory on better throttle response centers around electrical noise (think of an aftermarket stereo that's not grounded well and whines when you accelerate - same principle here).

Some have not seen any benefit, but most have seen at the very least a steadier idle. As I stated, my erratic idle is smooth as **** now and I am getting slightly better throttle response, but I'm fairly highly modded. Some guys with stock trucks who have done this are reporting a day/night difference in throttle response and even transmission shifts.

Best thing about this is it's virtually a free mod and even if it doesn't do a thing for you, it can't hurt anything. You're simply hooking up an extra ground wire.

 

[TexasRammer]

I'm on this like a BOSS! Mine has been acting like that lately but only when the truck is cold. Once it warms up it's fine. I have some extra wire here from an audio build I'm about to do. It darn sure can't hurt to try this.

My question is...where did you hear about this and what was someone doing to think they should ground the TB in the first place?

i dont think it will work for yours, only the hemis and newer 4.7s have a drive by wire i believe

 

[05singlecabHEMI]

So, all your doing is putting a ground from 1bolt of the throttle body to a factory ground? Hmm. Sounds interesting. I might have to give this a try some time soon.

 

[03MopaRamman]

I just been too Lazy and haven't decided whether to go 10 or 4 Guage and like Ryan said maybe I will get nothing out of it (not stock) but if it works I'll be happy as every once in a while mine will get Choppy.