surging idle on 6 speed

[hasselbach]

I've noticed for a long time, if I am coasting in my 05 nv5600, and say you are coming up to a stop light, and kick it out of gear, the idle speed surges up and down until you stop (about 2-300 rpm).



I know there is a TSB about the fuel control mod, but wondered if this is the fix.



anyone esle notice this?

 

[RankRam]

When you roll to a complete stop does the idle settle at 750 rpm? If it does then I would say It's normal, my 99 did it and the 05 as well.



Come to think of it my 96 V-10 did it too.

 

[KNeeley]

Perfectly normal.

 

[formula]

Mine has done the same thing since day one. It'll go from about 600 - 900 rpm a couple of times. Always settles right back to 750 rpm.



Sean

 

[SP Diesel]

From our experience this is fairly common, but it can be greatly reduced if not eliminated by raising the high pressure fuel at idle a little bit.

 

[macdaddy]

I've noticed for a long time, if I am coasting in my 05 nv5600, and say you are coming up to a stop light, and kick it out of gear, the idle speed surges up and down until you stop (about 2-300 rpm).



I know there is a TSB about the fuel control mod, but wondered if this is the fix.



anyone esle notice this?

It's normal!!



The ECM gets confused from input from the speed sensor while in neutral.



Mac

 

[Cattletrkr]

It's normal!!

The ECM gets confused from input from the speed sensor while in neutral.

Mac

So would leaving the trans in gear and just shoving in the clutch stop the "bounce"? I guess I haven't experimented with this before. Mine's done it forever. Aside from being annoying, it doesn't seem to bother anything.

 

[formula]

So would leaving the trans in gear and just shoving in the clutch stop the "bounce"? ... ... ... ...

Nope, it will still do it.



Sean

 

[JCleary]

In my experience, it seems that a tap on the brakes will settle the idle.

 

[GGranahan]

i have the exact problem with my 05 6sd. it stinks. my 99 and 96 trucks do not do this. i have been to the dealer 4 times and they say no check engine light no-fix. they did perform the fuel relay replacement bulletin but this did nothing except make my mileage go from 15 down to 10-11. why? they say they have talked with both chrysler zone and cummins and that they are not aware of this problem. next they want to bring the truck in and do a sequence of pressure measures. i am reluctant to be the guiea pig. especially when its very obvious that the problem is speed related-input from speed sensor or how the computer is reading the data-a probable software problem. i assure you this is a rampant problem i have seen many entries on this site concerning it as well as i have talked to people who do not have this problem with their gen 3 6sds. dealer says all people with this problem must get their dealer to notify the chrysler headquarters(forgot what name of this division is) and once enough complaints are received they will investgate. believe me this is not normal. a $40000 truck that surges and 2 $28000 trucks that do not. please reply to ggranahan.

 

[sag2]

GGranahan

It is normal for the manual trans trucks to do it, and besides, what does it hurt?

 

[betterthanstock]

My 03 will go to 850 until I stop, then back to 750. No surging.

Fuel cuts out completely if your foot is off the accelerator and rpm are above 1100 rpm. (not just diesels, all fuel injected engines do that) At 1100 fueling resumes to the fast idle setting (you can feel it wanting to maintain speed), so I don't coast to stoplights, I keep it in gear until 1200, then coast.

Saves some fuel that way. Maybe slightly different for later years, but I'm sure it's similar.

 

[hasselbach]

GGranahan

It is normal for the manual trans trucks to do it, and besides, what does it hurt?

It shouldn't be normal, it is a computer glitch. And it drives me nuts. Not all cars or trucks do it. I wish there was a fix for this.