problems.

For discussing injector selection, manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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R100RT
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Re: problems.

Post by R100RT »

Where you riding in your movies? (your location?)
My signature is missing when I post to Microsquirt, but I'm in BC near Vancouver.
classic-indy
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Re: problems.

Post by classic-indy »

The snowmobile is North of Hamilton/Burlington. I'm currently living out in Kitsilano. Hoping to get back east for a couple full days of tuning.....
dontz125
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Re: problems.

Post by dontz125 »

Are your injectors Hi-Z or Lo-Z? You have PWM Current Limit% set to 75% and PWM Time Threshold set to 1.0 msec. If you have Hi-Z injectors, this should be 100% and 25.4 msec. This, plus the reduced rail pressure, will significantly affect the performance of your injectors.
classic-indy
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Re: problems.

Post by classic-indy »

Hi- Z injectors with PWM set to 100% and PWM time threshold to 1.0 msec. This is one of the things I first looked at. I am going to be home February 9-11 and I will be able to work on this project. I'm going to try my 3 bar regulator but with my duty cycles being so high, I don't think the injectors will flow enough fuel to get under the 85% duty cycle max. I have purchased 85 lb/hr Lo-Z injectors, if the increased pressure over the fuel rail does not get me enough flow I will install the 85 lb/hr injectors.

Does 0.5 bar in the fuel rail make that much of a difference for fuel flow, I would think atomization would suffer first.
dontz125
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Re: problems.

Post by dontz125 »

The .msq posted December 30 shows PWM limit set to 75%. Also, flow through an orifice is proportional to the square root of the pressure differential across the orifice; quadruple the dP, double the flow. Unless I've got my signs reversed, 2.5 bar vs 3 bar means a flow reduction of about 9%.
classic-indy
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Re: problems.

Post by classic-indy »

Interesting I just looked at the .MSQ seems you are correct. They are Hi-Z injectors, I started out with Low-Z and the EFI system was using too many watts. So I switched a bunch of stuff around to reduce power consumption. The injectors were the main reduction in power consumption.......I know what happened.

If you look at the required fuel. You'll notice 85 lb/hr injectors, which are Low-Z. I must have attached the wrong .MSQ after my reconfiguration for the larger injectors I had ordered.

I will still try the 3.0 bar regulator before switching to the 85lb/hr Low-Z injectors, would be much easier for me to utilize the Hi-Z injectors for power consumption reasons.
classic-indy
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Re: problems.

Post by classic-indy »

I didn't have much luck with just changing the Pressure Regulator. So I dropped in the larger 85 lb/hr injectors. I can now pump enough fuel, Duty cycle goes up to about 65%. Theses are looking like a good match as at the moment and I haven't been able to reach full rpm. Idle quality seems to be just as good also. Now that the engine is running better, I have discovered by looking at the data logs I have other issues. Tach signal, and erratic MAP readings are the next thing to iron out.
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