Starting Engine from a Stop

[Eighthtry]

The PowerBoost doesn't employ conventional auto start/stop. The truck transitions smoothly from electric to hybrid drive in most modes, and immediately when your foot lifts off the brake in sport/tow haul. I have no idea what the passenger was complaining about. To date every passenger I've had marvels at the vehicle operation.

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[Eighthtry]

That is my experience with my daughter's PowerBoost. I learn a lot in these forums.

 

[Gros Ventre]

Picture of the dash when engine off... Oil pressure is zero.

 

[Snakebitten]

Yep. Looks like Ford isn't trying to hoodwink the XLT owner.

 

[Gros Ventre]

I cannot figure Ford out. It is apparent that on some trucks, when engine off, the oil pressure doesn't quite go to zero, while on others (eg mine) it does. Since we know the gauge is driven by a switch, why would they do that? Then on the 12 vdc system voltage it goes to alot of odd levels. Today, with ambient temperatures in the +30s, I drove some 300+ miles on interstates. System voltage began around 15VDC at startup and dropped as I'd expect to around 13.1 VDC. Then stayed there for the next several hours. I'm beginning to wonder if the temperature sensor for the system voltage regulator/computer is located in some odd place that stays cold when outside temps are well below 32ºF.

 

[Gros Ventre]

Got it. The description is that of a single rotor gerotor type pump (positive displacement) with a solenoid operated output pressure control. I suspect that this solenoid then controls ether the spring tension or a variable orifice in the relief valve setup. The use of the default setup is a good one since loss of voltage ensures ful flow.

OK, Do you know what the high pressure setting is? This article shows 20-30 psi for the low setting but does not go on to mention that high pressure setting. I'm seeing the effects of system hammer on my oil filters that I infer comes from the shift to the high pressure setting. I'm contemplating installing a Canton Racing Products accumulator as an oil hammer suppressor.

 

[scott011422]

Are you using the factory filter?

I have not seen any evidence of filter collapse using the stock filter.

The accumulator would defiantly help with this if it can be connected between the pump and the filter. On the other hand, The accumulator would drain every time the ICE turns off and then have to refill everytime the ICE turns back on. This would lessen the flow and pressure to the rest of the engine on startups. Are you not concerned by this? Or would you also be installing some valving to control oil flow into and out of the accumulator?

 

[Gros Ventre]

Are you using the factory filter?

I have not seen any evidence of filter collapse using the stock filter.

The accumulator would defiantly help with this if it can be connected between the pump and the filter. On the other hand, The accumulator would drain every time the ICE turns off and then have to refill everytime the ICE turns back on. This would lessen the flow and pressure to the rest of the engine on startups. Are you not concerned by this? Or would you also be installing some valving to control oil flow into and out of the accumulator?

Still thinking it through... The Canton Racing Products accumulators have a refill orifice in it to limit the parasitic flow of oil back into the accumulator. So its just not an issue. Also keep in mind that as the accumulator refills the inflow is proportionately getting lesser and lesser as the bubble compresses. The outflow into the engine takes several minutes to reduce to zero. In my observation of my powerboost the off-times are shorter that the drain times these see. Still, do you know the higher pressure setpoint? It's regulated by the setting of the relief valve on the pump output.
I'm putting in a remote filter setup. As part of this I'll have a real live pressure gauge. With that I'll have a better idea of what's going on with this Ford double pressure setup and how fast it changes things. Keep in mind the shift in pressure happens when a solenoid changes the volute geometry. Likely that is a snap and thus there may be a pressure wave going thru the system. Effectively that's a hammer wave. Note since an air bubble is likely trapped in an oil filter (if the bubble is big enough) that would mitigate the pressure wave when it hit the filter.

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