D6T High Idle seems low

[satkinson]

Morning

I have a D6T s/n JRW00674 is making 1900 rpm on high idle this seems a bit low to me, does anyone know the correct figure and how to adjust it if needed, i have full ET and am reasonably proficient on it.

Thanks Steve

 

[ahart]

Go into ET and look at Actual engine RPM compared to Desired engine rpm, if they match, it’s doing its job. If not, something is going on. That would be my first thing to check.

 

[satkinson]

Go into ET and look at Actual engine RPM compared to Desired engine rpm, if they match, it’s doing its job. If not, something is going on. That would be my first thing to check.

Thanks il give that a try much appreciated

 

[Nige]

If there is a discrepancy between Desired & Actual RPM the first thing to check IMO would be the fuel supply rather than attempting to adjust parameters with ET. Just a thought.

 

[satkinson]

Nigel

I checked the figures between actual and desired and they match but I'm only getting max revs of 1930 I thought it seemed on the low side, when I go into the calibration menu on ET and try and change it the high idle is pre set to 2080 rpm and it won't let me change this figure.
I'm wondering if I'm not getting full travel of the deacelerator but it doesn't look like there's any adjustment that can be made its just hitting the stops.
Fuel supply is all good the tractors just had new filters and the injectors have recently been replaced, there's no active fault codes on ET

 

[Mobiltech]

You can read deceleration and throttle status on ET to see if it’s at 100 percent.

 

[satkinson]

You can read deceleration and throttle status on ET to see if it’s at 100 percent.

Mobiltech

Yes I looked at that I'm at 2% when the deacelerator is fully released, possibly this is where I'm loosing a few revs

 

[Nige]

Yes I looked at that I'm at 2% when the deacelerator is fully released, possibly this is where I'm loosing a few revs

It's a PWM sensor. The chances of it reading absolutely 0% (or 100% when you move the control the other way) are somewhat slim......

Question: Does the tractor appear to have plenty of power when pushing a blade full of dirt.?

 

[satkinson]

It's a PWM sensor. The chances of it reading absolutely 0% (or 100% when you move the control the other way) are somewhat slim......

Question: Does the tractor appear to have plenty of power when pushing a blade full of dirt.?

Nigel

Yes no issues at all with power it runs perfectly seems to have plenty of torque, just doesn't seem to make full rpm, our older d6t with LKJ prefix rev to 2200 rpm, this one seems a bit flat

 

[Nige]

Yes no issues at all with power it runs perfectly seems to have plenty of torque, just doesn't seem to make full rpm, our older d6t with LKJ prefix rev to 2200 rpm, this one seems a bit flat

OK, I see where you're coming from. It is more of a perception from the guy in the seat and/or anyone on the ground that the machine isn't pulling its weight because the RPM doesn't sound as high as "it ought to be".

This is something that has come up more & more now the emissions era is well and truly here. Although TBH there are often sound reasons for it. Think of it this way - when the tractor is pushing a blade full of muck it needs maximum TORQUE, not maximum power. It's always the case that the RPM for Max Torque is significantly lower than the RPM for Max Power.

A lot of latest generation powertrain/engine software has the capability to detect when the machine is pushing (or not pushing. i.e. transmission NOT in 1st speed forward) and will reduce the desired engine RPM under those conditions to one where the engine is actually producing more torque that it would have done at Full Power RPM. I don't know if that makes sense.

 

[thepumpguysc]

Idk “spit” about electronic engines.. but I will say, on a mechanical injection engine, hi idle “no-load” rpm’s are set 10% higher than full load rpm’s..
I know.. the grown ups are talking.. sorry,

 

[Nige]

Idk “spit” about electronic engines.. but I will say, on a mechanical injection engine, hi idle “no-load” rpm’s are set 10% higher than full load rpm’s..
I know.. the grown ups are talking.. sorry,

And this engine is no different despite the fact it's electronic. The HINL according to specification (on the dyno) is 2080 RPM, Full Load is 2000. The tolerance on both of these values +/- only 10 RPM. In my experience electronic engines generally have tighter control on RPM values than those with mechanical governors.

Depite the above numbers - all bets are OFF once the engine is installed in a machine and connected to the other ECMs in the system. Inputs from other ECMs can affect the engine RPM, for the reasons I explained earlier. Sometimes to do in-frame engine tests using ET you have to put the engine in "Dyno Mode" to nullify the effect of other inputs external to the engine ECM.

 

[Nige]

I don’t know if it’s the case on this particular tractor, but I do recall a parameter from the dim & distant past that was something like “transmission requested engine speed” which indicated a higher authority than the engine ECM was in charge of controlling engine speed.

 

[ahart]

Might not be a separate parameter in ET but it very well could have an input on the max RPM. To test, I’d do a no load full RPM reading, actual and desired, and then a 3rd gear stall full RPM reading, actual and desired. Should tell you if the transmission is affecting the max desired RPM.

 

[Mobiltech]

The D6T’s that have gears such as 1.5 and 2.5 do limit the rpm in those gears to give you the feeling of another speed.
What is the high idle rpm when rolling with no load in each gear?
Also can you connect et to the other d6 and see what it’s parameters for rpm are?

 

[nicky 68a]

There’s probably nowt wrong with your D6T.Cast your mind back to when the T series first took over from the R series and all the drivers would be saying how terrible they were and ‘Cat don’t make them like they used to’ etc,etc.
Well,I owned both D8R and D8T travtors at the same time and the R was a murderous brute of a thing that would cause the ground to shake in its boots when it started up.It would attack any pile of muck in sight and flatten it.
Very impressive……
But,my D8T just quietly goes about its business without noise and fuss and very efficiently does the job.
As for my D9T,that thing sounds like a Toyota Prius when it starts up and goes to work.You hardly notice it working,but you’ll soon notice it’s moved half a hillside in a mornings shift.
It’s just the perception of the operator .