fuel pump controller

fuel pump controller

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Discussion

F.C.

Original Poster:

3,896 posts

207 months

Sunday 20th April 2014
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Anyone on here using a "rising rate" fuel pump controller?
If so does it work well?
Any do's or don'ts?

MarkWebb

983 posts

216 months

Monday 21st April 2014
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I am looking at buying this one http://www.professional-products.com/secure/upload...
However having written them a no of emails I have yet to get a reply.
Your input appreciated as always

F.C.

Original Poster:

3,896 posts

207 months

Monday 21st April 2014
quotequote all
MarkWebb said:
I am looking at buying this one http://www.professional-products.com/secure/upload...
However having written them a no of emails I have yet to get a reply.
Your input appreciated as always
Interesting, that one does away with the regulator.
I'd imagine that any pump that works with that would need to run comfortably at lower voltages for extended periods of time, during cruise for instance.
I would think not all pumps will be linear in their voltage versus pressure curve and may have trouble if the curve is not similarly linear.
On balance I think I would like to keep a regulator and just have a low / high rpm switch over, ie. upto 2500rpm low volume above 2500rpm high volume.

hedgefinder

3,418 posts

169 months

Monday 21st April 2014
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sod it, I am going to fit 2 pedals,crank and sprockets to get over all these fuelling issues.. and stick 2 fingers up to Cameron and his fuel duty cronies...
break out the wine and the dremel..

anonymous-user

53 months

Monday 21st April 2014
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F.C. said:
I'd imagine that any pump that works with that would need to run comfortably at lower voltages for extended periods of time, during cruise for instance.
I've not found a std pump you can't run on a lower voltage, providing the driving system keeps the current ripple undercontrol (ie, probably uses a synchronous rectification type architecture) as that minimises the motors torque fluctuations and hence any vibration or noise. On my twin series 044s all i hear when the system is up to pressure but engine off is a very quiet "click clack" of the pumps internal one way ball valves oscillating slightly on their seats. Once any significant fuel flow occurs (ie, anything above about warm idle) the system is completely silent as my controller drivers the pumps with a PWM frequency above the human audible spectrum.

Steve_D

13,737 posts

257 months

Monday 21st April 2014
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Max_Torque said:
......my controller.......
When can we buy one or buy the circuit diagram and parts list?

Steve

F.C.

Original Poster:

3,896 posts

207 months

Monday 21st April 2014
quotequote all
Max_Torque said:
I've not found a std pump you can't run on a lower voltage, providing the driving system keeps the current ripple undercontrol (ie, probably uses a synchronous rectification type architecture) as that minimises the motors torque fluctuations and hence any vibration or noise. On my twin series 044s all i hear when the system is up to pressure but engine off is a very quiet "click clack" of the pumps internal one way ball valves oscillating slightly on their seats. Once any significant fuel flow occurs (ie, anything above about warm idle) the system is completely silent as my controller drivers the pumps with a PWM frequency above the human audible spectrum.
So using a digital signal to control pump duty?

MarkWebb

983 posts

216 months

Monday 21st April 2014
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I think this controller works on PWM hence no problem with low volts. That is one of the questions that I would like them to answer. There certainly are PWM controllers out there.

Steve you and me both. I have asked him a number of times.

SchimmS

258 posts

257 months

Monday 21st April 2014
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anonymous-user

53 months

Monday 21st April 2014
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All these controllers will work using a Pulse Width Modulated (PWM) driving technique. This is because a linear control strategy would be un-acceptably lossy at these power levels.

Power = volts x current.

For a fuel pump: current = torque = fuel pressure and voltage = pump speed = fuel volume


So, generally, the pump current will be broadly constant with supply pressure, lets say at 10 amps.

At full speed, where battery voltage is applies directly to the pump, pump power is 12v x 10A = 120watts.

So, to run at half speed, a linear system would have to find a way of dissipating 60watts as heat somewhere in the system, which is simply not practicable.

By using a pwm driving architecture, the system creates a lower drive voltage with only two power semiconductor states (On & Off) so the losses are very much lower (in the order of a couple of watts, depending on the power devices used)

anonymous-user

53 months

Thursday 24th April 2014
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I wonder how many of those pump controllers they sell? I guess a few for LS (re)engined cars that have a returnless system as std these days?

SchimmS

258 posts

257 months

Thursday 24th April 2014
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Max_Torque said:
I wonder how many of those pump controllers they sell? I guess a few for LS (re)engined cars that have a returnless system as std these days?
Can`t be too many but I like the idea of not pumping 220l/h around the engine bay at full fuel pump speed. Changing diameters on different connections always changes the flow rate and fuel pressure and with it the boiling point of the fuel.

macgtech

997 posts

158 months

Friday 25th April 2014
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So presumably this reduces flow to a manageable level without going low enough to adversely affect pressure?

SchimmS

258 posts

257 months

Friday 25th April 2014
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macgtech said:
So presumably this reduces flow to a manageable level without going low enough to adversely affect pressure?
The fuel rail pressure is maintained at any given engine load by varying the fuel pump speed. A pressure sensor in the fuel line is connected to the fuel pump controller which then controls fuel pump speed.
It`s very simple and effective, by varying the fuel pump speed you supply the fuel rail constantly but don`t circulate excess fuel which simply heats up.

anonymous-user

53 months

Friday 25th April 2014
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Pretty much all OEM vehicles moved to "returnless" fuel systems about 10/15 years ago, when the tightening emissions regulations mean't that evaporative emissions from the fuel system became critical. By having a pump that controls rail pressure to a target, without a conventional regulator or spill back mean't much reduced bulk fuel upheat, and as a result, significant reduction in the vapour pressure in the tank and hence the volume of hydrocarbon vapour that the activated carbon canister had to catch!

F.C.

Original Poster:

3,896 posts

207 months

Friday 25th April 2014
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I take it the carbon canister is in the vent line from the tank(s)?
what sort of size are these? weight wise what are we talking, 1KG carbon?

macgtech

997 posts

158 months

Friday 25th April 2014
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SchimmS said:
The fuel rail pressure is maintained at any given engine load by varying the fuel pump speed. A pressure sensor in the fuel line is connected to the fuel pump controller which then controls fuel pump speed.
It`s very simple and effective, by varying the fuel pump speed you supply the fuel rail constantly but don`t circulate excess fuel which simply heats up.
I was wondering exactly that - whether or not it had a pressure sensor as part of a feedback loop or if it needed controlling some other way.

anonymous-user

53 months

Friday 25th April 2014
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macgtech said:
SchimmS said:
The fuel rail pressure is maintained at any given engine load by varying the fuel pump speed. A pressure sensor in the fuel line is connected to the fuel pump controller which then controls fuel pump speed.
It`s very simple and effective, by varying the fuel pump speed you supply the fuel rail constantly but don`t circulate excess fuel which simply heats up.
I was wondering exactly that - whether or not it had a pressure sensor as part of a feedback loop or if it needed controlling some other way.
You can just control rail pressure by controlling to a fixed pump current (as current = torque = pressure) but most systems use an injector differential pressure sensor to allow accurate closed loop control.

Sensor sits on fuel rail, and has a "T" off to measure plenum air pressure, that way, the engine control unit can control injector differential pressure:



or



anonymous-user

53 months

Friday 25th April 2014
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F.C. said:
I take it the carbon canister is in the vent line from the tank(s)?
what sort of size are these? weight wise what are we talking, 1KG carbon?
Depends of the application and the emission std to which the car is designed. They can be physically quite large, say 3L volume and approx 2kg with valve and pipes etc



anonymous-user

53 months

Sunday 27th April 2014
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SchimmS said:
How much do those^^^ systems cost btw? They both look engineered down to a price rather than properly designed.........