set engine tickover speed to 900rpm on a D5

davebb · Feb 14th, 2019, 20:41

Hi if I set the engine tickover speed to 900rpm on a D5 (std is 700rpm) will it use much more fuel ?
Dave

cheshired5 · Feb 14th, 2019, 21:43

If you can find fuel flow data in the technical specs in Vida, you could then monitor fuel pressure data at the 2 different engine speeds to make a calculation or I guess you make a Diesel Purge style fuel loop in the engine bay and run half a litre of diesel through at the 2 different rpm.
Time the results then extrapolate the findings.

I suppose the more obvious questions are why do you want a higher idle and how can you achieve it?

davebb · Feb 14th, 2019, 22:04

Hi Simon
I have fitted a top engine mount polybush and as you know they can give some bad vibration, but if I hold the revs at 900-1000rpm the vibration is nearly gone,
I do like the way the car feels with the top polybush ,
I will be re-programing the ecu to take the rpm to 900 from 700,
Dave

cheshired5 · Feb 14th, 2019, 22:33

An interesting little project Dave.
I can't see how any increase in fuel consumption would be high enough to cause an issue in fact I bet it's pretty negligible.

oragex · Feb 14th, 2019, 22:38

In theory, if it's only a matter of idling mixture, I don't think it would make an important difference, maybe 1-3% more fuel burning. But I wonder if it won't also affect the way the computers measures the fuel mixture for the entire rpm range.

davebb · Feb 14th, 2019, 22:40

Hi Simon
I did think I would not notice using any more fuel,
I will try doing it soon as I have cloned some ecu,s so I can have a play
I will post when I have done tried it out,
Dave

davebb · Feb 14th, 2019, 22:53

Quote:

Originally Posted by oragex

In theory, if it's only a matter of idling mixture, I don't think it would make an important difference, maybe 1-3% more fuel burning. But I wonder if it won't also affect the way the computers measures the fuel mixture for the entire rpm range.

Hi In the Bosch ecu there is a idling speed map that the ecu uses to change the speed/temp, so when the car is started it will rev higher when cold until the engine is warmer, and then it settles to 700rpm, I will be changing just the 700rpm to 900rpm
Dave

Stephen2015 · Feb 15th, 2019, 08:39

Is the car an Auto? I like the way both my Volvos move along at 700 RPM in idle speed in traffic. Would setting the RPM to 900 make this a wee to fast? saves on the breaking?

Just something to bear in mind.

davebb · Feb 15th, 2019, 08:52

Hi no it is not a auto,
Dave

Brendan W · Feb 15th, 2019, 10:16

Wonder what your top speed would be without touching pedal

Feb 14th, 2019, 20:41	#1
davebb Premier Member Last Online: Apr 14th, 2024 23:55 Join Date: Aug 2013 Location: Emsworth,hants	set engine tickover speed to 900rpm on a D5 Hi if I set the engine tickover speed to 900rpm on a D5 (std is 700rpm) will it use much more fuel ? Dave

Feb 14th, 2019, 21:43	#2
cheshired5 Premier Member Last Online: Dec 26th, 2021 13:42 Join Date: Dec 2013 Location: Crewe	If you can find fuel flow data in the technical specs in Vida, you could then monitor fuel pressure data at the 2 different engine speeds to make a calculation or I guess you make a Diesel Purge style fuel loop in the engine bay and run half a litre of diesel through at the 2 different rpm. Time the results then extrapolate the findings. I suppose the more obvious questions are why do you want a higher idle and how can you achieve it? __________________ 2002 S60 SE D5 Manual 209000 miles

Feb 14th, 2019, 22:33	#4
cheshired5 Premier Member Last Online: Dec 26th, 2021 13:42 Join Date: Dec 2013 Location: Crewe	An interesting little project Dave. I can't see how any increase in fuel consumption would be high enough to cause an issue in fact I bet it's pretty negligible. __________________ 2002 S60 SE D5 Manual 209000 miles

Feb 14th, 2019, 22:38	#5
oragex Premier Member Last Online: Jul 26th, 2021 21:24 Join Date: Jun 2013 Location: Coldnada	In theory, if it's only a matter of idling mixture, I don't think it would make an important difference, maybe 1-3% more fuel burning. But I wonder if it won't also affect the way the computers measures the fuel mixture for the entire rpm range. __________________ Several Volvo Repair Videos https://www.youtube.com/playlist?lis...ECTts0FSVSOT_c

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Feb 14th, 2019, 22:04	#3
davebb Premier Member Last Online: Apr 14th, 2024 23:55 Join Date: Aug 2013 Location: Emsworth,hants	Hi Simon I have fitted a top engine mount polybush and as you know they can give some bad vibration, but if I hold the revs at 900-1000rpm the vibration is nearly gone, I do like the way the car feels with the top polybush , I will be re-programing the ecu to take the rpm to 900 from 700, Dave

Feb 14th, 2019, 22:40	#6
davebb Premier Member Last Online: Apr 14th, 2024 23:55 Join Date: Aug 2013 Location: Emsworth,hants	Hi Simon I did think I would not notice using any more fuel, I will try doing it soon as I have cloned some ecu,s so I can have a play I will post when I have done tried it out, Dave

Feb 15th, 2019, 08:39	#8
Stephen2015 S60 D5244T4 Last Online: Jul 26th, 2023 17:31 Join Date: Apr 2015 Location: Norwich	Is the car an Auto? I like the way both my Volvos move along at 700 RPM in idle speed in traffic. Would setting the RPM to 900 make this a wee to fast? saves on the breaking? Just something to bear in mind.

Feb 15th, 2019, 08:52	#9
davebb Premier Member Last Online: Apr 14th, 2024 23:55 Join Date: Aug 2013 Location: Emsworth,hants	Hi no it is not a auto, Dave

Feb 15th, 2019, 10:16	#10
Brendan W Premier Member Last Online: Apr 2nd, 2024 19:50 Join Date: Dec 2007 Location: Wexford	Wonder what your top speed would be without touching pedal

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