dpuma8 Posted May 16, 2011 Share Posted May 16, 2011 I read the FAQ on fixing the noisy Walbro fuel pump by adding a Carter low pressure pump pumping into a surge tank. I would also like to run a set up just like this but is there any way to run dual pumps off of the L28ET ECU? Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 16, 2011 Share Posted May 16, 2011 Take the hot wire from the Fuel pump relay going to the back of the car (there is a power and ground.)You want to bypass the fuel pump modulator on the negative side of the stock fuel pump, take that wire directly to ground, and do not use the harness back to the front of the car---or bypass the modulator in the kick panel. Attach these wires to the coil and ground connections of TWO 30A (or suitable) relays fed off suitable sized (I used circuit-breakered 10 gauge from the positive post on the battery) to the common switched terminal on the relay, then run from each relay's switched output terminal to each of the pumps (I ran 12 gauge wire)---I grounded the pumps locally to an isolated buss bar that connects both to the chassis and via an 8 Gauge wire back to the negative post on the battery. Basically you set up the stock fuel pump relay to trigger two larger relays that are fed by a REAL wire to the back of the car without a lot of power drop. Even on a stock pump, you can hear the thing spin faster because the power drop from the front of the car to the back is negligible. That, and at idle you don't have the modulator slowing the pump down to keep it quiet (it will get loud if you don't have sufficient fuel bypass capacity, btw.) The stock modulator really slows down the pump to decrease fuel flow...keeping it quieter. It's pretty simple, mine is probably overkill on wiring sizes, but I wasn't sure what pump I would eventually run. This setup runs dual Porsche Pumps, plus the boost pump to the surge tank. (Yeah, you got it, substitute "three" for "two" in the above instructions! It's JDM old-school technology....leastwise that's where I picked it up!) It works nicely when you ditch the stock ECCS and go to real standalone ECU for proper fueling! Quote Link to comment Share on other sites More sharing options...
dpuma8 Posted May 16, 2011 Author Share Posted May 16, 2011 Thanks for the response. I am going MS as soon as I get my $5,500 tax return. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 17, 2011 Share Posted May 17, 2011 WOAH! Made a little error on the W-4 eh? Quote Link to comment Share on other sites More sharing options...
dpuma8 Posted May 29, 2011 Author Share Posted May 29, 2011 Yep. Normally I like to pay a bit but at least this error went this way Quote Link to comment Share on other sites More sharing options...
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