Which cylinders?

[CUMAPART]

On the new ECM fast idle option, which cylinders are cut off? Is it the same three all the time? I'm just a little skeptical on shutting down the same three cylinders each morning or night during warm up for 4 months out of the year. It's been cold here and I just keep her plugged in for 2-3hrs before take off, let her idle for 5-10 min, and keep her under 1800rpm til the temp gets up. I don't know if I want her chugging on 3 cylinders. Just Curious.

 

[CoastyAV8R]

The latest TDR mag lists the TSB for the cold idle mod but doesn't say which three get shut down. The TSB # is 18-31-1 is you feel like looking it up.



Pat

 

[Texas Diesel]

The 3 cylinder thingy goes away as soon as you come off idle.

 

[Bad340fish]

I don't see it hurting anything, if the motors running they are stll gonna be going up and down. All the reflash does it turn the fuel off to them so the other 3 have to work a little harder and build some heat up. my . 02

Clark

 

[waltk]

Thinking about which cylinders are cut-off at the 3-cylinder-cold-start situation, it's kinda obvious that a pattern of every-other cylinder in the firing order would be cut-off, otherwise the firing impulses would be out of balance... I'll go out on a limb and assert my belief that cyl #1 fires and the next in firing order does *not*, following cyl (third in order) does fire, etcetera through sixth in firing order (which does not fire).



Walt K.

 

[PKozlowski]

When I had mine done (and it works great!)



My mechanic did some research and made some

phone calls and "they" said that it rotates

the cylinders so it's not the same 3 all the time.

 

[waltk]

I dunno, I won't argue what was told... but intuitively other than an 'every-other-cylinder-in-the-firing-order' shutdown scheme for the three cylinder warmup would result in undue vibrations... My simple-mind says every-other is what happens; *perhaps* each invocation will operate the opposite set of cylinders, maintining the every-other ordering...



Walt K.