Auto Idle

[nymoment]

I have an 07 Valencia Freight liner xcs Cummings 300 h.p. isb . My problem is that when i first start it
the engine monitor flashes auto idle and the amp gauge drops to no charge then pops back up to normal
then drops back down and up again. If i shut down and restart it may or may not do it again.Some tines i have to restart three times .Any thoughts.
Thanks Gary

[Triker56]

Under the dash they should be a idle switch at the test connection that you can bump up the idle speed a little. See it that stops the problem.

[Ranger Smith]

Could also be possibly the intake heaters cycling onn and off

[dsbike]

Originally Posted by Ranger Smith

Could also be possibly the intake heaters cycling onn and off

This is what Freightliner in Gaffney SC told me , of course I have a newer engine 2013 & 400hp

[stik]

Originally Posted by nymoment

I have an 07 Valencia Freight liner xcs Cummings 300 h.p. isb . My problem is that when i first start it
the engine monitor flashes auto idle and the amp gauge drops to no charge then pops back up to normal
then drops back down and up again. If i shut down and restart it may or may not do it again.Some tines i have to restart three times .Any thoughts.
Thanks Gary

Pretty sure you are seeing the intake grid cycling on and off which is NORMAL. Does it stop after a few minutes? Does appear to do it longer in colder temperatures? If yes to both, it is most likely the intake grids, they are the replacement of the old time glow plugs. They take a tremendous amount of power. Next time you start it, give it 5 minutes and see if it doesn't stop. Re-starting several times is hard on your batteries and is defeating the purpose of the girds, which is to heat up the intake air when you first start up the beast.

[nymoment]

Thank you all for the quick responses. Going out this after noon for the weekend will let you all know how it works out.
Gary

[sdlowe11]

I've also experienced this during cool and cold weather. My fix is to run my engine block heater for 2-3 hours before starting up, anytime the outside air temperature is below 50 degrees. You could try using your block heater several times in a row before startup to confirm whether the intake heater is causing the issue you see.

[FIRE UP]

Well Gang,
Ours is an '04 Itasca Horizon, 36GD with the C-7 330HP CAT engine. It too uses the "Heat grid" or intake heater(s) for prewarming of the intake air, prior to startup. The normal sequence is, Key on, all lights on (that is, lights and icons in "Annunciator panel") which, incudes the "Wait to start" light/icon. When that goes off, I then crank the big beast over.

Now, right after it starts, I take a gander at all the important stuff like oil pressure and, voltage. The O/P goes to around 55-60 and the voltage immediately heads to 13.5-13.8 plus or minus. But, there is no fluctuation. It will remain higher like that for a while, oh, around maybe 5-10 minutes and then settles down to around 13.0-13.2.

I've seen my "wait to start" come back on, after the engine has started, only a time or two, in the three years we've owned the coach. And, if and when it has, it's within a few seconds or so, right after it fires up. But, there's no fluctuation in the voltage gauge.

But, all this means nothing if, the manufacturer, in this case Cummins, has setup the heat grid and, engine ECM etc. to cooperate and tie into, ambient air temp conditions etc.
Scott

[nymoment]

Just got back from the weekend .Seems like that the intake heaters are making it go into auto idle. The only thing is it will do it for about 10 to 15 mins. then the idle goes high . If i shut it off and restart it is fine.
Gary

[SeattlePirat]

Our cummins idles for a few minutes then goes high. Touch the brake pedal and back to normal. I have been told the reason for this, and it makes sense, there is nothing wrong according to FL and Cummins