Cubflyer Posted June 16, 2022 Share Posted June 16, 2022 1 minute ago, wamcneil said: Same type that folks use in FASS installs as a dummy load to fool the ECM into thinking the factory lift pump is still present. Yep, and the "dummy load" is a resistor... or stated another way... a "coil" as in "relay coil"....Or another way.. a "DC motor winding" Looks like that AirDog harness will take care of the ECM and like JimJ said: 'I'm surprised that Airdog doesn't have that answer'...... But if you also install a fuel pressure gauge, you will get the answer to that pretty quickly... Ken Link to comment Share on other sites More sharing options...
jacwjames Posted June 16, 2022 Share Posted June 16, 2022 That and the ECM is only looking for 30-60 seconds as to whether the lift pump is running. Will it even send voltage after that? I guess you could put a meter on it while the engine is running and see what voltage it is sending. 1 Link to comment Share on other sites More sharing options...
wamcneil Posted June 16, 2022 Author Share Posted June 16, 2022 (edited) Yeah, I might need to put a voltmeter on it and just see what it's doing... Since the tiny current of a relay was enough to fool the ECM, I was assuming it held a small voltage on the circuit and used that to determine if the pump was good. Kind of like my car can sense when a bulb is bad, even when the lights are off. If the harness doesn't work out as-is I could just cut off the ECM plug and use to make a dummy load. Edited June 16, 2022 by wamcneil Link to comment Share on other sites More sharing options...
tmw188 Posted June 21, 2022 Share Posted June 21, 2022 (edited) What about this scenario, what happens if the FASS pump looses power supply or quits running for whatever reason, can the CAPS pump still be able to draw fuel up to itself? So after posting the paragraph above I found a couple of Q&A’s that seem to answer that question saying that it will allow pass thru with limited filtering. I will call FASS this morning to get more info. Edited June 21, 2022 by tmw188 Link to comment Share on other sites More sharing options...
JDCrow Posted June 21, 2022 Share Posted June 21, 2022 2 hours ago, tmw188 said: What about this scenario, what happens if the FASS pump looses power supply or quits running for whatever reason, can the CAPS pump still be able to draw fuel up to itself? So after posting the paragraph above I found a couple of Q&A’s that seem to answer that question saying that it will allow pass thru with limited filtering. I will call FASS this morning to get more info. My lift pump and all the hoses are still there and can be swapped back at anytime Link to comment Share on other sites More sharing options...
tmw188 Posted June 21, 2022 Share Posted June 21, 2022 Yep. Link to comment Share on other sites More sharing options...
JDCrow Posted June 21, 2022 Share Posted June 21, 2022 24 minutes ago, tmw188 said: Yep. Here is the FASS no filters other than the OEM primary/Secondary. Pump is right in between the two filters. And a pic of the lift pump that I ran the hoses to and capped off the ends. There already is a return line OEM. This kit just used that line and does not need a hose ran back to the tank like others have done. So far so good. Link to comment Share on other sites More sharing options...
tmw188 Posted June 21, 2022 Share Posted June 21, 2022 (edited) JD oh ok I forgot you saying earlier that you just choose to replace the lift pump only with the FASS model pump only. Edited June 21, 2022 by tmw188 Link to comment Share on other sites More sharing options...
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