Hondata

Just as a data point -- after installing my w/i, I get a few false knocks (my engine bay noise has gone up a lot) and my laptop disconnects quite a bit. I switched to a shielded cable and I found one that generally doesn't disconnect, but I still get it from time to time. Seems activating the w/i pump really produces some efi or something. Not quite sure.

I wonder if there would be any merit in putting a ferrite on the activation wire as it connects to a relay coil right next to the big honk'n water/meth pump. Perhaps it's getting exposed to a lot of efi.

Thoughts welcome.

Wayne

Are you using a relay? You might be able to use a multimeter on AC setting to measure the EMI on the lines around the pump (I know this worked when we have the problems with the non resistor spark plugs).

The other issue is the way Honda has wired the ECU ground - all the current sunk by the ECU to ground goes to the ground point which normally bolts to the manifold. This includes the main relay, fuel pump relay and probably your pump relay. This is why this ground is so important - Honda should really have taken it back to the battery negative terminal. Measure between this point and the battery negative terminal to check for any voltage difference and/or current flow. Also it may be worth using a diode to block the back emf from the relay coil. Some relays have these diodes built in.

Hondata wrote:Are you using a relay? You might be able to use a multimeter on AC setting to measure the EMI on the lines around the pump (I know this worked when we have the problems with the non resistor spark plugs).

The other issue is the way Honda has wired the ECU ground - all the current sunk by the ECU to ground goes to the ground point which normally bolts to the manifold. This includes the main relay, fuel pump relay and probably your pump relay. This is why this ground is so important - Honda should really have taken it back to the battery negative terminal. Measure between this point and the battery negative terminal to check for any voltage difference and/or current flow. Also it may be worth using a diode to block the back emf from the relay coil. Some relays have these diodes built in.

I actually have my own diy grounding which includes battery cable with crimped on copper connectors that go from the head where you suggest moving the ground to and runs to the battery negative terminal -- a nice fat ground wire. I also added a new chassis ground by sanding a spot off on the frame rail under the battery tray and ran another new large gauge battery wire with copper ends from the neg terminal to the frame... so, I think I've got grounding done pretty well.

The pump itself grounds to a sheet metal screw that is screwed into the aluminum bracket I mounted stuff to -- that same screw has it's own grounding wire running from it to the OEM ground location on the fender well.

I am using a relay, but the relay is right next to the motor. Do you think there would be value in moving the relay say perhaps a foot away instead of less than an inch? It might be that the coil used in the relay is picking up some of the fields generated by that big honk'n motor.

Wayne

PS: Pictures of my grounding from a year or two back...

http://www.we-todd-did-racing.com/wetod ... NDE%3D.jpg
http://www.we-todd-did-racing.com/wetod ... NDE%3D.jpg
http://www.we-todd-did-racing.com/wetod ... NDE%3D.jpg
... yeah it was dirty then ;).