Steve Bull Posted September 17, 2017 Report Share Posted September 17, 2017 Im trying to set up the ECU for idle control with a 2 wire solenoid but cant seen to get it to maintain a stable tick over. Any ideas. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 18, 2017 Report Share Posted September 18, 2017 Post a map and log: https://www.youtube.com/watch?v=_P1LRANeO4A Quote Link to comment Share on other sites More sharing options...
Steve Bull Posted October 9, 2017 Author Report Share Posted October 9, 2017 Got another question, im using Aux 4 as a PWM to control my fuel pumps. I have a Solid State Relay SSR, to do the high current switching and its set at 1800 hz. This allows control of the pumps to lower the pressure at low demand. At present tick over @35% PWM, gives 30 psi of fuel and maintains a steady 4.5 V Its yet to be set up fully but what would you recommend to to use as the "Y" axis on the PW table. At the moment its TPs % but i thought it might better to either MAP or % of the fuel table while keeping the "X" axis as RPM. I also need to control the Electric PAS pump, I do intend to use another SSR but could the ECU be used on the low side to control it again PWM. Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 10, 2017 Report Share Posted October 10, 2017 I would not be adjusting FP speed so much that effects fuel pressure, you really want to aim to keep differential fuel pressure constant under all conditions for the fuel equation to work properly. For your PWM table I would just do 2D, with inj duty cycle as the axis. In most typical setups required fuel pump flow is directly proportional to inj DC, there is no need for any other variable to be considered. Quote Link to comment Share on other sites More sharing options...
Steve Bull Posted October 10, 2017 Author Report Share Posted October 10, 2017 the only reason for dropping the FP that low on tick over is that the fuel pressure regulator, through manifold depression, does the same. The pumps can flow 660 lt of fuel per hour which is far too much unless at max boost and revs. The fuel was getting quite warm and pumps drawing too much current when they didn't need to . Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 10, 2017 Report Share Posted October 10, 2017 Sure, you still want to use PWM, but dont throttle it back to the point were it effects fuel pressure, you want enough excess fuel there so the FPR can do its job and control the pressure with a little headroom left for safety. When I say "pressure", I mean differential pressure which should be near the same no matter what boost or vacuum is applied to the reg diaphragm. Quote Link to comment Share on other sites More sharing options...
Ducie54 Posted October 10, 2017 Report Share Posted October 10, 2017 Here is some data i took when working out what PWM DC to run. You can see there is a point where the pressure drops considerably, Quote Link to comment Share on other sites More sharing options...
Steve Bull Posted October 10, 2017 Author Report Share Posted October 10, 2017 That seems similar to what i get but the FP regulator is set to 3 Bar. Is there any way to prime the pumps with the use of the timers. Quote Link to comment Share on other sites More sharing options...
Simon Posted October 10, 2017 Report Share Posted October 10, 2017 You could set a Virtual aux set to Fuel pump and use this to trigger the GP PWM output. Quote Link to comment Share on other sites More sharing options...
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