Belize Off Road Team

Well i have had it since i bought the truck, but i thought i would post before i swap it out cause i like it.

Ok, when the A/C system has a charge this happens:
With the fan on my average idle is 800-1000RPM, however when the fan is turned off I drop DOWN to 400-500RPM and it sounds like i have a 440 under the hood. Now it has baffled all the mechanics i have told, and my friends scratch their heads.

YES i do know that it does this so the A/C does not stall the truck when it is on...but NEVER should it be such a great difference in idle RPM. The sound goes from a constant growl to a chug chug chug similar to the 69' 440 Hemi.

It causes no problems, I don't want to get rid of it, I just thought i would share and see if anybody does know what causes the 3VZ-E to do this. And if i can i want to do it on my 5VZ-FE cause i am going run 2-3 foot pipes off the headers and it would sound like a real 440 then! nice and LOUD.

Want a video of this? just PM me.

zeeth2800

throttle position sensor...
same thing happened to my buddys truck

Jay351

Wierd. Opposite happens to me. I turn the fan on my rpms do down a little bit...

You should hear mine idle at 400rpm! Its so bad, but sounds so cool...

Cyberman

Sounds to me like the a/c idle up isn't working properly.

abecedarian

and the base idle speed is off too

Cyberman

Ya, I read that wrong the first time. The base idle should be around 800 RPM. And the A/C idle up is supposed to keep the idle up, not have it go that high.

Belize Off Road Team

Yeah, it idles really high, like i said 800-1000 as long as the fan is on, when i turn it off it drops to 400-500RPM. so am i getting this, its the A/C idle adjusment that makes it idle the way it is?

abecedarian

yep. with the a/c off it should idle ~750-800. With it on, it should idle about the same if just slightly higher. The a/c idle up valve has a large plastic screw on it you can use to adjust the idle with the a/c on.

swapped89

If the a/c idle screw doesnt work. Try the engine idle screw its on the throttle body stairing right at you just behind were the throttle cable moves the flap inside the throttle body. the throttle body is connected to the intake plenum and the black hose for the intake. its a flat head screw almost half inch in diameter. very easy to adjust engine idle rpms.

Cyberman

800-1000 is not high, it's actually the base idle (per FSM). I'd turn the idle up on the throttle body, then turn the A/C idle up down, until the idle in both situations is between 800-1000 RPM.

Belize Off Road Team

I have no problem with the idle, i like being able to shut off the fan and here it chug chug like a 440. And when it gets to 15C my start up idle is 1500RPM until the cooling fan turns off. I have no issue, i know how to adjust the idle, i was not sure what made it idle like it did, cause i want to repeat it on my 3.4L cause it will be sooo loud when i do dual straight pipes of the headers.

Cyberman

well, I guess now you know...

Bigblock

Wont work on the 3.4!No idle adjustment.
Bigblock

Bigblock

BTW there's no such thing as a 440 HEMI.There was a 440 and then there was a 426 HEMI.
Bigblock

Belize Off Road Team

oh, thanks for the info bigblock.

Tested but not produced:
The Chrysler 300 with 440 Hemi
In all fairness, the 413 Wedge was the better torque producer, along with a hydraulic lifter set up for the valves for less intense maintenance. Until you got past 100 mph, the 413 was marginally faster than the 392 Hemi.
One of the spinoffs from the A990 full racing Hemi program that was built and tested but not produced was the 300 Hemi model engine, meant for the 300 letter series sport sedan cars. 440 ci was obtained by boring the 426 block to 4.32 inch from the 4.25 inches. The 3.75 inch stroke remained the same.