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AldoQ wrote:Is it possible to use return-less fuel system? i have a ford fuel pressure sensor

Do you know the calibration for this ford fuel pressure sensor? What is the part number? Is it a 3-wire with voltage output or something more complicated?

I guess the firmware would need a change to account fuel pressure in http://rusefi.com/wiki/index.php?title=Manual:Software:Fuel_Control but that should be easy.

Or is it more than just adjusting injection duration, do I need to actually control the fuel pump in order to control the fuel pressure?

On a return less fuel system, I'm thinking it's a PWM controlled fuel pump which is controlling a pressure at the other end of the rail.

Exactly. It will not be as simple. You will need to compensate fuel amount in conjuct.with actual pressure. Rate of press. drop in line depends on actual fuel consumption, .... It will not be simple.

It's not necessarily that complicated- it really depends on the car and how 'returnless' the system actually is.
For example: on '99 to '05 (NB) Miatas the fuel system is called returnless, but it actually has a return integrated in the tank which is responsible for keeping the pressure constant. So the fuel line to the engine has a constant pressure by mechanical means, (pressure relief valve) but is dead-headed at the end of the fuel rail. There are two pulsation dampers in the system in order to deal with short-term variations. The disadvantages of this system is that the fuel pressure is not referenced to the intake and that at low flow-rates the fuel in the rail heats up causing the engine to run lean.

Such a system does not require any special effort at all and can be used with rusefi out of the box.

Any system that requires electronic stabilization of fuel pressure will need a controller which, AFAIK, can not easily be done with the current status of rusefi out of the box.

hi
Bosch 4-pin FRP sensors
2260004, 3F2Z9F792CA, 3F2Z9G756AA 3F2Z9G756AB, 3F2Z9G756AC, 3F2Z9G758AC, from some fords
1. FORD CROWN VICTORIA 2005-2011 V8 4.6L Engine
2. FORD E-150 2005-2008 V8 5.4L Engine
3. FORD E-250 2005-2008 V8 5.4L Engine
4. FORD E-350 SUPER DUTY 2005-2008 V10 6.8L Engine
5. FORD E-350 SUPER DUTY 2005-2008 V8 5.4L Engine
6. FORD E-450 SUPER DUTY 2005-2008 V10 6.8L Engine
7. FORD E-450 SUPER DUTY 2008 V8 5.4L Engine
8. FORD ESCAPE 2005-2008 L4 2.3L Engine
9. FORD ESCAPE 2005-2008 V6 3.0L Engine
10. FORD EXPLORER 2004-2010 V6 4.0L Engine
11. FORD EXPLORER 2006-2010 V8 4.6L Engine
12. FORD EXPLORER SPORT TRAC 2004-2005 V6 4.0L Engine
13. FORD EXPLORER SPORT TRAC 2007-2010 V6 4.0L Engine
14. FORD EXPLORER SPORT TRAC 2007-2010 V8 4.6L Engine
15. FORD F-150 2005-2008 V6 4.2L Engine
16. FORD F-150 2006-2008 V8 4.6L Engine
17. FORD F-150 HERITAGE 2004 V6 4.2L Engine
18. FORD F-250 SUPER DUTY 2005-2010 V10 6.8L Engine
19. FORD F-350 SUPER DUTY 2005-2010 V10 6.8L Engine
20. FORD F-450 SUPER DUTY 2005-2008 V10 6.8L Engine
21. FORD F-450 SUPER DUTY 2010 V10 6.8L Engine
22. FORD F-550 SUPER DUTY 2005-2010 V10 6.8L Engine
23. FORD F53 2006-2009 V10 6.8L Engine
24. FORD F53 2004 V10 6.8L Engine
25. FORD FIVE HUNDRED 2005 V6 3.0L Engine
26. FORD FIVE HUNDRED 2007 V6 3.0L Engine
27. FORD FOCUS 2005 L4 2.0L Engine
28. FORD FOCUS 2004-2005 L4 2.3L Engine
29. FORD FREESTAR 2004-2007 V6 3.9L Engine
30. FORD FREESTAR 2004-2007 V6 4.2L Engine
31. FORD FREESTYLE 2005 V6 3.0L Engine
32. FORD MUSTANG 2005 V6 4.0L Engine
33. FORD MUSTANG 2005-2010 V8 4.6L Engine
34. FORD TAURUS 2004 V6 3.0L Engine
35. LINCOLN TOWN CAR 2005-2011 V8 4.6L Engine
36. MERCURY GRAND MARQUIS 2005-2011 V8 4.6L Engine
37. MERCURY MARINER 2005 L4 2.3L Engine
38. MERCURY MARINER 2005 V6 3.0L Engine
39. MERCURY MONTEGO 2005-2006 V6 3.0L Engine
40. MERCURY MONTEREY 2004-2007 V6 4.2L Engine
41. MERCURY MOUNTAINEER 2004-2010 V6 4.0L Engine
42. MERCURY MOUNTAINEER 2006-2010 V8 4.6L Engine
43. MERCURY SABLE 2004 V6 3.0L Engine
etc
in ebay $20

some data of Ford P/N 3U2Z-14S411-UC
0.50 volts – 0 PSI
1.2 volts – 10 PSI
1.65 volts – 20 PSI
2.2 volts – 30 PSI
2.75 volts – 40 PSI
2.89 volts - 43.5 PSI
3.45 volts – 50 PSI
3.9 volts – 60 PSI
4.6 volts – 70 PSI

Alternate sensors
but with out intake reference or fuel temp, but with map sensor and some math correction can work?
http://www.ebay.com/itm/Pressure-transducer-or-sender-100-psi-stainless-steel-for-oil-fuel-air-water-/261260635816 with good info

this sensor is used to control PWM to fuel pump , so low fuel flow to engine , low duty cycle , max power from engine , max duty cycle to match fuel flow and pressure capabilities of fuel pump , maybe can add a voltage booster for short periods of time with power adders ie turbo super charger or n2o

point apart
im think in lpg liquid injection, tank pressure direct to injector, with a proper sensor to measure the gas pressure, and maybe a fuel injector of a direct injection system,
regards

Do you have a driver for the fuel pump? The drivers on the frankenso can not drive the fuel pump directly. But they could drive an external external device. Also do you have a particular fuel pump in mind? I'm mostly looking to learn about what kind of inertia it would have.

If the fuel pump has low inertia, we could try the same control algo that we used for the alternator. Basically if you are above target pressure turn off, if you are below target turn on, allow changing state once ever 100mS or some similar base time. I like this concept as you are measuring the fuel pressure. I could see how you could have a low pressure limit, which would provide warnings if you ever had a lack of fuel pressure due to a plugged fuel filter, worn out pump, etc.

I know that mechanical regulators adjust the fuel based on the manifold pressure, such that the pressure differential is always the same. Do PWM return-less systems track the MAP, or does the fuel calculations need to adjust the fuel trim? I suspect that they adjust the trim, as the manifold pressure can change much faster than I would expect the pump can change.

hi
the ford pressure sensor have a port for intake reference and can measure the fuel temp
the specs i have of the fuel pump
· Min Voltage Input:6V
· Max Voltage Input:18V
· PRV Activation:100PSI
· Flow Rate: 255LPH/43PSI(13.5V)
· Current(40PSI):<13A(13.5V)
· Overall Length (tip to tip): 5"(123MM)
· Weight:12.6oz (360g)
· Length of Pump Body Metal Case: 3 1/8"(80MM)
· Pump Body Diameter: 1 1/2"(39MM)
· Inlet Fitting: 7.7mm ID, 11.0mm OD
· Outlet Fitting: 5/16" hose clamp
regads

for drivers , an mosfet and schottky flyback diode
frankenso can drive directly the mosfet, or i need an mosfet driver?
regrads

Frankenso can drive the MOSFET with the HI/LO drivers. That seems to be a small diameter, I think you would be OK with simple on and off control based on the target pressure.

Keep in mind that the MOSFET will make many watts of heat and will need significant heat sinking.

Do you know if the fuel pump has that check valve which prevents backward flow? I recall most normal pumps have this valve.

Hi the fuel pump have chek valve
If the MOSFET is only on off and have low Ohm when on,. Why will disipate much heat?

Lets assume the MOSFET has an Rds of 0.01 ohms.As well lets assume the diode conducts 0.7V when allowing 13A of current through it. That's a beefy diode.

When conducting current the MOSFET will dissipate P = I^2 * R = 13A^2 * 0.01 ohms = 169 * 0.01 ohms = 1.69 watts. When the fly back diode conduits, it will start to dissipate P = I * V = 13A * 0.7V = 9.1 watts.

With those assumed values, and looking at the longer term average dissipated watts, you'll dissipate some where between 9.1Watts and 1.69 Watts. How many watts you dissipate exactly depends on how much of the time the MOSFET is on, or how many times it transitions to off and causes the fly-back diode to engage.

Also keep in mind that your diode will probably have a recovery time. Such that if the MOSFET turns the pump on while the pump is in active fly-back decay, the diode will be a dead short to GND for some period of time. This period of time will also cause I^2 * R losses.

stefanst wrote:It's not necessarily that complicated- it really depends on the car and how 'returnless' the system actually is.
For example: on '99 to '05 (NB) Miatas the fuel system is called returnless, but it actually has a return integrated in....

So in such system you have constant press. in rel. to ambient press. But true returnless does not. So you will have to deal with more variables. For racing engine - maybe, for any "wider" engine ...?
did you mention Miata system only? Such system has European Mondeo with Duratec and it does not have pump controler at all.

i have lying around and mosfet PSMN022-30PL , and 20tq040 Schottky Rectifier which im plan to use , the next step is to make the fitting for the pressure senor

AldoQ wrote:the next step is to make the fitting for the pressure senor

So what kind of control logic are you going to try? PID pwm based of pressure sensor or a curve based on RPM or else?

russian wrote:

AldoQ wrote:the next step is to make the fitting for the pressure senor

So what kind of control logic are you going to try? PID pwm based of pressure sensor or a curve based on RPM or else?

PID pwm based of pressure sensor

With a Tr and Tf time in the nS range, I would suggest using the above and below target to set if you turn on or off instead of a PID loop. A PID loop will be complicated to tune. Also you could use the base timer of 10mS or 1mS, I forget what the fastest timer is, perhaps russian can comment about the fastest easily available timer. For that MOSFET the faster the better.

I do not see a recovery time for the diode. This may be a problem, or it may note be a problem. It's certainly worth some caution and analysis. During the diodes recovery time, it dead shorts, which can cause the MOSFET to fail. So I suggest keeping an eye on the peak current passed by the MOSFET.

Just an on off control?

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Yes I believe you will find good success with on and off control. Once every 1mS or 10mS, check if you are above or below your target pressure. Then turn on or off the pump if you are above or below accordingly.

Ok[SMILING FACE WITH OPEN MOUTH]

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