PWM fuel pump setup. Why is it not more common?
#41
I have never dissected an electric fuel pump. I'm sure some designs are ahead of their time, and some far behind. I figured if someone knows, I would ask the question.
#42
I took apart another Bosch pump some 25 years ago after I broke it.
I'd soldered a pickup pipe into the tank of my Mini to fit a Bosch pump, but never had any sort of filter on it. A small piece of solder managed to get into the pump and seize it.
TBH it was nothing fancy....big motor and a roller cell pumpy bit at the bottom. Small piece of solder got jammed in one of the rollers.
It wasnt an 044 but fairly sure 044's are of similar design. Although any 044's I've used in recent years also have a filter screen inside the base..
I tried to put the pump back together again, but could never get the crimped bit at the top to seal again....they're clearly not designed to be taken apart and tried to put back together by idiots lol
I'd soldered a pickup pipe into the tank of my Mini to fit a Bosch pump, but never had any sort of filter on it. A small piece of solder managed to get into the pump and seize it.
TBH it was nothing fancy....big motor and a roller cell pumpy bit at the bottom. Small piece of solder got jammed in one of the rollers.
It wasnt an 044 but fairly sure 044's are of similar design. Although any 044's I've used in recent years also have a filter screen inside the base..
I tried to put the pump back together again, but could never get the crimped bit at the top to seal again....they're clearly not designed to be taken apart and tried to put back together by idiots lol
#43
Tesla Motor Design Circa 1900's
Hi ALL, I NEVER stated "today's standards".
I too have disassembled the 044 finding a similar rotor construction, a design over 100 years old.
This process was BEFORE plastic was invented that is now used to reduce rotor friction.
The modern PMM design (twenty+years ago first) is common to fuel pumps today.
This style is natural PWM, Brush-less, sealed rotor, low current consumption
The internal Field Correction is a read using a Hall Sensor and a measurement of the Pole Magnet position.
Lance, BTW my first motor inspection was done at the age of three, my toy train set.
I too have disassembled the 044 finding a similar rotor construction, a design over 100 years old.
This process was BEFORE plastic was invented that is now used to reduce rotor friction.
The modern PMM design (twenty+years ago first) is common to fuel pumps today.
This style is natural PWM, Brush-less, sealed rotor, low current consumption
The internal Field Correction is a read using a Hall Sensor and a measurement of the Pole Magnet position.
Lance, BTW my first motor inspection was done at the age of three, my toy train set.
#44
#45
Two Stroke Engine Inspection
Hi G, my first (own) one cylinder engine inspection was when I found a Lawn Mower, a two stroke engine, set out in the neighbors trash. (Fourth Grade)
Though to be fair, my father let me "wash" his motorcycle parts before that inspection.
Lance
Though to be fair, my father let me "wash" his motorcycle parts before that inspection.
Lance
#46
12 Second Club
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From: From Ohio now in that state up north
I don’t know this for sure but I think the oem pumps that are PWM are different than the standard pumps so there might be some reliability or performance issues. That being said injector dynamics is coming out with a pump and pwm controller so it is definitely on the aftermarket radar. Would like to see how it does though would be a great thing if the pumps will work with it.
#47
I don’t know this for sure but I think the oem pumps that are PWM are different than the standard pumps so there might be some reliability or performance issues. That being said injector dynamics is coming out with a pump and pwm controller so it is definitely on the aftermarket radar. Would like to see how it does though would be a great thing if the pumps will work with it.
So anything ID have coming out wont be anything new in that sense.
But there should be no issues PWMing a motor when done correctly...pretty much any motor as it is the correct way to vary the speed of a standard DC motor.
#48
I've sent a message to VaporWorx inquiring about a PWM slave pump module. Most all their stuff is self contained meaning it's a standalone setup already. I'd love to be able to PWM my primary pumps to keep power draw down, fuel temps lower and extend the life of the pumps. If they can't help out I may be able to convince Dave Steck to do something since he's already worked on that stuff on the OEM side of things.
#50
Not really, but two 450 pumps running full blast all the time is a lot of wasted energy and does heat it up. In this cold weather it doesn't take long for my fuel temp to rise up to 120degF
#51
Do you have a very small fuel tank ?
Even on mine...even after driving for 4 hours only very rarely have I seen running temps that high, although that was with a pair of 044's
One of those times was last year when stuck in some shitty traffic for ages on a very warm day ( Warm here would be 75-80degF lol )
Temps might get to around 120degF on mine with lots of sitting about due to heat soak with a lot of stop starts. But once the pumps are running again and fuel circulating they always drop.
I do have a reasonably large fuel tank though, almost never less than 20 litres in it.
I will be switching to 450's though and changing to an in-tank setup just as soon as I can get the time to do it. I've 3 and a hanger all sitting waiting !
So it will be an interesting swap. Will probably just use 2 of them though, but figured may was well install all 3 anyway.
Even on mine...even after driving for 4 hours only very rarely have I seen running temps that high, although that was with a pair of 044's
One of those times was last year when stuck in some shitty traffic for ages on a very warm day ( Warm here would be 75-80degF lol )
Temps might get to around 120degF on mine with lots of sitting about due to heat soak with a lot of stop starts. But once the pumps are running again and fuel circulating they always drop.
I do have a reasonably large fuel tank though, almost never less than 20 litres in it.
I will be switching to 450's though and changing to an in-tank setup just as soon as I can get the time to do it. I've 3 and a hanger all sitting waiting !
So it will be an interesting swap. Will probably just use 2 of them though, but figured may was well install all 3 anyway.
#52
I realize I'm late to this party but I thought I'd throw this out there anyhow just as an FYI... Subaru uses PWM for fuel pump control, or at least they did from about 2004 to 2012, which is when I was paying attention. I suspect they still do.
The pump in my car runs 33%, 66%, or 100% depending on battery voltage, boost, and injector duty cycle. I swapped the factory pump for an Aeromotive 340 with no other changes and it still works fine. The ecu just toggles between those three levels depending circumstances, the fuel pressure regulator takes care of the rest.
So anyway, using an Arduino to drive a MOSFET-based pump controller makes perfect sense to me. If you use an FPR and a return-style fuel system, the control logic doesn't need to be finely tuned, it just needs to command enough duty cycle to avoid losing pressure during high boost, high flow, and/or low voltage. If you want to get really fancy you could try measuring the flow out of the regulator, and run enough duty cycle to keep that above some threshold.
The pump in my car runs 33%, 66%, or 100% depending on battery voltage, boost, and injector duty cycle. I swapped the factory pump for an Aeromotive 340 with no other changes and it still works fine. The ecu just toggles between those three levels depending circumstances, the fuel pressure regulator takes care of the rest.
So anyway, using an Arduino to drive a MOSFET-based pump controller makes perfect sense to me. If you use an FPR and a return-style fuel system, the control logic doesn't need to be finely tuned, it just needs to command enough duty cycle to avoid losing pressure during high boost, high flow, and/or low voltage. If you want to get really fancy you could try measuring the flow out of the regulator, and run enough duty cycle to keep that above some threshold.
#53
I've never measured the output from a Subaru controller, but dont think it's anything special nor can it handle the current of larger pumps ? Even a 340 is probably pushing things ?
Like it or loathe it.....the SSR's do actually work ok for this. I've had a pair of 450's running now for a while on my own car and other than some issues I caused myself at the start it's been working fine since.
Like it or loathe it.....the SSR's do actually work ok for this. I've had a pair of 450's running now for a while on my own car and other than some issues I caused myself at the start it's been working fine since.
#55
My current fuel injector flow bench uses a pair of $30 ebay pumps and an arduino nano with a MOSFET. Anything up to decapped stock injectors works fine on a single pump. Aftermarket injectors, I either have to turn the duty cycle down, only test 4 injectors, or PWM both pumps.
Turning the duty cycle down usually results in slightly lower results because of a ~1 ms dead time, so I adjust it between 60 and 80 and let it go. Testing 4 injectors at a time takes too long. PWM on a pair of ebay pumps at the highest frequency I can achieve on the nano works perfect. I run a fuel pressure sensor in the rails, and along with the stock truck regulator/return, I can maintain 58 PSI of fuel pressure.
Turning the duty cycle down usually results in slightly lower results because of a ~1 ms dead time, so I adjust it between 60 and 80 and let it go. Testing 4 injectors at a time takes too long. PWM on a pair of ebay pumps at the highest frequency I can achieve on the nano works perfect. I run a fuel pressure sensor in the rails, and along with the stock truck regulator/return, I can maintain 58 PSI of fuel pressure.
#56
My current fuel injector flow bench uses a pair of $30 ebay pumps and an arduino nano with a MOSFET. Anything up to decapped stock injectors works fine on a single pump. Aftermarket injectors, I either have to turn the duty cycle down, only test 4 injectors, or PWM both pumps.
Turning the duty cycle down usually results in slightly lower results because of a ~1 ms dead time, so I adjust it between 60 and 80 and let it go. Testing 4 injectors at a time takes too long. PWM on a pair of ebay pumps at the highest frequency I can achieve on the nano works perfect. I run a fuel pressure sensor in the rails, and along with the stock truck regulator/return, I can maintain 58 PSI of fuel pressure.
Turning the duty cycle down usually results in slightly lower results because of a ~1 ms dead time, so I adjust it between 60 and 80 and let it go. Testing 4 injectors at a time takes too long. PWM on a pair of ebay pumps at the highest frequency I can achieve on the nano works perfect. I run a fuel pressure sensor in the rails, and along with the stock truck regulator/return, I can maintain 58 PSI of fuel pressure.
#59
A buddy of mine uses them on his 6-second blown big block to log boost in various places. They are 3 wires, 5v ref, ground, signal. You can either tap into the 5v reference for TPS/MAP on a stock PCM or pin into one of the unused ones on the stock PCM.