EZ EFI for marine use questions

DooSPX · #1 (**permalink**) 08-10-2010, 01:02 AM

Is the EZ EFI system safe to use in a marine environment with a raw water cooling system? Also, I know the system uses a water temp sensor for main control readings, can I still use my factory water temp gauge and warning buzzer/light setup with your EZ EFI? BTW, the engine is a Indmar marine Ford 351W.

Thank you!

FAST Tech Maxwell · #2 (**permalink**) 08-10-2010, 07:46 PM

The coolant needs to get to at least 140 degrees F in order for the EZ ECU to learn.

Chances are that the voltage curve is different between your gauge and our ecu/sensor setup. I would install the FAST sensor in addition to the one that is already there.

Hope that helps.

DooSPX · #3 (**permalink**) 08-10-2010, 09:40 PM

So no way to lower the water temp huh? that stinks.
these tournament ski boats run very cool sense they are under a lot of load. my 351W has a 140* T-Stat and will barely hit 140 unless ran at WOT for a while. but at 3600rpm or 36mph for the course, its normally at 130-135*.

TurboNova · #4 (**permalink**) 08-11-2010, 01:30 AM

I have a fix for marine use. It will keep the temp 16.

DooSPX · #5 (**permalink**) 08-11-2010, 09:39 AM

You have a fix? Can you give me for details please?

TurboNova · #6 (**permalink**) 08-14-2010, 11:32 PM

e-mail me and I will explain.

dsmmace · #7 (**permalink**) 05-07-2011, 12:14 PM

I can't email you or PM you so I thought I would post on here to help document for others.

I am installing the EZ-EFI on my Mercruiser, I found spacer places that I can mount an oxygen sensor in-between the manifolds and risers. Other that that I am curious to how you recommend routing the the return line. Here's my line of thinking let me know what makes the most sense:

Factory design goes like this, vented plastic tank to water separator housing/filter, from there it goes to the pump and then carb.

My idea was to still use the water separator and route the return line back to that housing to avoid warmer fuel getting back to the tank to avoid vapor lock.

Or run the factory setup and run a return line back to the tank and make sure there is a really good vent on it.

Other than that, it all seems very straightforward for install, I do plan running a few extra grounds to avoid potential issues there. Am I missing anything?

TurboNova · #8 (**permalink**) 05-07-2011, 09:00 PM

I have been using a resistor to make se the water temp shows 140 or above all the time or at least after it is warmed up.

As for the return line it needs to return before the pump but not right before the pump. Most aftermarket ecus need a return style fuel system so they will build a small tank the the large fuel tank fills then the pump pulls from there and the return can go there too.

Your water separator might also work just don't introduce any air bubbles into the incoming fuel stream. Think fish tank here it works the same.

We have been using the O2 both on the XFI and ez EFI by putting it between the manifold and the exhaust pipe leaving the riser. Most of the headers that are stainless have a double wall turn at the manifold and we weld an O2 bung inside and out there.

dsmmace · #9 (**permalink**) 05-08-2011, 03:23 PM

I wondered about the possibility of bubbles, but in theory that should only happen if there was an air leak???

I can't return it back in after the fuel pump, there isn't enough fuel line length with the pump being mounted on the block and then the filter after that. I have seen some factory marine return lines setup that way.

TurboNova · #10 (**permalink**) 05-08-2011, 04:51 PM

Air bubbles will happen even with no air leaks. The return has to be before the line gets to the pump or it will act like a fish tank. Merc Marine puts a tee before the pump and runs the return there but that is really not the right way either.... it adds air bubbles into the system. There really needs to be a smaller tank between the pump and fuel tank that the fuel line returns to.