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Discussion Starter · #1 ·
Over the last couple of days, I've noticed that my engine of my 2003 TrailBlazer (Vortec 4200 I-6 engine) has been idling very low. Initially, when I start the vehicle up for the first time in a given day, it will settle junder under 1,000 RPMs (as expected).

However, later in the day, it'll idle around 600 RPMs. I never paid much attention to this until the other day I went from park to reverse / park to drive and when I pressed on the gas, it almost stalled on me.

I thought maybe I picked up some bad gasoline, but I don't think that'd explain the this very low idle.

What should the engine idle at after it's warmed up?

Also, does anyone know if this is a known issue and if any PCM updates have been released to fix this?

Thanks for any info.
 

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Your poor TB is giving you some trouble... mine has done the almost stall thing 3 times and has stalled once when putting into reverse. I havent done anything with it yet though, because I am still in denial. Even if there is something wrong with it I still love her. I think there is a thread about this vehical in the complaint line section.
 

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What is wrong with a 600-rpm idle?
My "aging" 4.3 V6 idles at 550-rpm.
No dies, no stalls, and no lag at all.
I would see a problem with anything
higher than 600-rpm from my truck.

Does the manual say what the idle is
suppose to be? I would guess ~600.

The Dodge Ram Hemi trucks have had
a "stall" issue when changing gears and
it was resolved by a software upgrade.
With ETC these days, the computer has
all control over what is going on, so this
would make me think there is a problem
with the software.
 

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Discussion Starter · #4 ·
Thanks for the input. Someone told me I could forcefully reboot the computer if I remove the negative connection from my battery and let it set for a while. The only reason I haven't done it yet is because I don't know if Theft Lock is engaged on my head unit.
 

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I've owned my TB since 05/01.

For the 4200 Vortec, 600 RPM idle is absolutely normal for a warm engine. When very cold, mine will idle at 1400 RPM. If you watch and wait RPMs will drop as it warms up.

There is nothing wrong with your vehicle unless the idle is irratic, or your engine stalls

Incidentally, bad gas, changing oil, etc wouldn't have any effect on Idle RPM. This is computer controlled and actuated via the electronic throttle control on the Vortec 4200.

here you go, yahoo searched 'vortec 4200 secifications'
first search result
Vortec 4200 Specs

Dan
 

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Originally posted by ERock@Jan 2 2004, 02:27 PM
Thanks for the input. Someone told me I could forcefully reboot the computer if I remove the negative connection from my battery and let it set for a while. The only reason I haven't done it yet is because I don't know if Theft Lock is engaged on my head unit.
If I am not mistaken there is a possibility if you do that, you might have to get some reprograming done. So you might as well get it looked at... eventhough the dealers service area will probably tell you they can'ty find anything wrong. Still havent got mine looked at(still in denial), not worried about the RPM, cause mine does not seem odd, it just drops and stalls when shifting in reverse sometimes.
 
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