Digital fuel pump controller ... to control pressure

[nkemp]

While looking for something else, I ran across an interesting idea/product. It is a closed loop computer control of the fuel pump. It measures the fuel pressure and then uses a pulsed width signal to modulate the pump to achieve the desired pressure.

It is based on the idea that pumps run 100% and the excess is sent back to the fuel tank. Running 100% is a higher than needed current flow, heats the fuel, and heats the pump possible lessening its life. In our system, it looks like we'd set it to 75 or 80 lbs. It could actually be used to eliminate the return line but that is a separate discussion.

This is not a new idea and as I understand it, some car manufactures operate their pump in such a way to eliminate the return line.

Thoughts? What do you think?

It would be desirable to modify the code a bit for our application and with enough ordered he may do so. Might there be interest in a group buy?

NOTE: the only downside applied to our system, both the OEM style and the new integrated pumps have a sump they pump from. Return fuel fills that sump and as such the sump can have a higher fuel level than the tank and it can run the tank fuel level very low. Lower than if no sump (some refer to it as a baffle)

[Bitsyncmaster]

I have thought of making the same thing. When I was designing my fuel cooler I though about modulating the pump to reduce the heating of the gas in the tank. But with our lambda system it would still need the tank return line via the frequency control unless you do make the mixture adjustment via the WUR port.

[nkemp]

In our system, I see retaining the return line and running the pump to output a pressure a bit over needed (80PSI ? or whatever PSI works). Fuel pressure is still regulated via the fuel pressure valve in the fuel distributer. The amount of fuel returned would be reduced, but not eliminated, from what we have today. Operating at a reduced pressure from the pump's minimum operating PSI would still be 20% less or more.

[FABombjoy]

Both the UTCIS and FrankenCIS perform a similar function using control pressure. I would think modifying system pressure via the fuel pump would be difficult due to the accumulator. Even if you bypassed the accumulator I would think the long fuel path would make finite changes difficult. Even the CP fueling schemes aren't super responsive and they run on a much tighter circuit.

[nkemp]

Both the UTCIS and FrankenCIS perform a similar function using control pressure.

The technique I mentioned does not perform the control pressure control that the WUR (or UTCIS and FrankenCIS) performs. The WUR (or UTCIS and FrankenCIS) would still be needed and need to operate as designed. The product I mentioned varies the fuel pump rate to reduce pressure to the fuel pressure regulator (from 100PSI, 110PSI, or whatever to something like 75PSI).

As far as the fuel accumulator and related go, the PI control software manages for that. For that matter, the fuel accumulator may help dampen oscillations. Regardless, given that the CIS fuel pressure regulator is in the circuit, we don't need tight control as long as it is set so that the minimum ripple is greater than the CIS need (I think it is 70PSI). So if the control oscillated from 72 to 82 PSI we would not care and that would still be less than the 100-115PSI some pumps are rated at.

BTW .. the FrankenCIS seems to have gone away. The UTCIS is way too expensive for what it is.

[FABombjoy]

Ahh, somehow I had a few wires cross while reading the description and thought it was for mixture control. Never mind me!

I agree the UTCIS is too expensive especially considering the company attitude regarding support. I was fortunate enough to pick mine up for about half price.

[FrankenCIS]

BTW .. the FrankenCIS seems to have gone away.

Hi folks,

The FrankenCIS project is still definitely alive and well