I figured out the MS3 grounds the fuel pump wire and doesn't send 12v like my stock ECU did, so I will be swapping some wires to make that work. However before I made the connection I plugged up my JimStim to test the fp pin and found that when the RPM's were at 0 the FP pin was putting out ~4v? Then when I turned on the RPM pot it would be a ground/0V.
I don't see how this would matter seeing how the relay wont be triggered with that but just wondering if there is a short on my board? The car ran with residual pressure in the lines for all ove 3 seconds then stalled so I think everything else is working properly. This was the first start up though...
Thank you for any insight you can give.
Fuel pump outputting voltage when not on...
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- Helpful MS/Extra'er
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Re: Fuel pump outputting voltage when not on...
With the FPR off, you should have 12v (VBatt, really) all the way from the relay coil pins to the transistor pin. No current, no voltage drop.
Next point - the FPR circuit is meant to drive a relay, not the pump itself. Even little bike pumps draw too much current for the V3.0 transistor.
Next point - the FPR circuit is meant to drive a relay, not the pump itself. Even little bike pumps draw too much current for the V3.0 transistor.
Temporarily shut down - back soon!
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
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- Super MS/Extra'er
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Re: Fuel pump outputting voltage when not on...
The ~4v is probably just there from the stims led indicator for fuel pump waiting to be turned on by grounding.
Find the Manuals up top under Quick links: Manuals.
Cheers Luke
Cheers Luke
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- Helpful MS/Extra'er
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Re: Fuel pump outputting voltage when not on...
Ah that makes a lot of sense. Ok. No worries. I'm sure it will work when I get home today. I'll just jumper the main power wire to the switch portion.