Egi/fuel pump relay failure

[thatvwguy]

Does anyone have a solution for failing egi relays?
I've had to replace 3 in the past 2 months, not sure what's causing it. From what I've read online it could be my upgraded fuel pump.

IMG_20181025_185018.jpg

What are some ways to fix this issue besides buying a spare and changing when needed

[greenMachine]

If it is related to the fuel pump (presumably a higher capacity pump that is drawing more current), the solution is to wire the pump to the battery through a relay triggered from your existing wiring. MTnet has plenty of info on this mod, if you need it, but that is it in a nutshell.

[manga_blue]

I'm not sure where to find it on mt.net.

Here are the relay pinouts on my car:

MAIN relay pinouts.jpg

I'd think about either replacing the existing relay with a heavier duty one on a small DIY loom or else adding a new relay and circuit switched at 85 from C on the old circuit and with a solid main supply to 30

[Magpie]

the Wire size maybe wrong for the current being drawn by the pump, upgrading the fuse/relay will not solve the voltage drop. The voltage drop will also impact on the pumps performance.

In the alternative wir3 the pump direct the battery using a relay and the OEM signal.

What is the draw of the pump you installed?

[greenMachine]

I am assuming you have an upgraded fuel pump, in which case MTnet thread Upgrading Fuel Pump Relay may be relevant.

If you haven't done that, it is probably something else that is putting a big current draw through that relay. What did you do to the car just before you started having these relays fail?

[mx589]

What pump you running ?
I had a walbro 190 for good couple of years no worries now stepped up to a 255

[The American]

Mine had a walbro 255(?) and was fine with the stock relay. When upgraded to Walbro 450, the relay failed immediately and repeatedly. Dedicated relay (as mentioned above) fixed it.

[thatvwguy]

What pump you running ?
I had a walbro 190 for good couple of years no worries now stepped up to a 255

I have a walbro 450


Thanks everyone for the suggestions, from reading this thread https://www.miataturbo.net/general-miat ... %60-94040/ it seems like the solution is to wire in a new relay and fuse directly from the battery to the fuel pump

[mx589]

Walbro 450 is big pump what kind of power kw at the wheels you aiming for mate

[thatvwguy]

Walbro 450 is big pump what kind of power kw at the wheels you aiming for mate

I am making roughly 150kwatw, I am only running this pump because I was planning to go e85 but changed my mind

[mx589]

Walbro 255 is good for just over a genuine 300kw at the wheels on 98 pump fuel so more than enough for 95% mx5 owners.

Walbro 460 is good for genuine 400kw at the wheels on 98 also.

Then you have the new helcat 525 walbro i think its called that flows around 10% more than the old 460

[greenMachine]

I am assuming you have an upgraded fuel pump, in which case MTnet thread Upgrading Fuel Pump Relay may be relevant.

What pump you running ?
I had a walbro 190 for good couple of years no worries now stepped up to a 255

I have a walbro 450
Thanks everyone for the suggestions, from reading this thread https://www.miataturbo.net/general-miat ... %60-94040/ it seems like the solution is to wire in a new relay and fuse directly from the battery to the fuel pump

You probably should also upgrade the wiring from the relay to the pump in that case. There is info there (probably in one or other, or both, threads) about using bigger wiring to the pump, and sources for the new bulkhead connectors.

[mx589]

Well said green machine I would upgrade the wiring also cheap and easy to do mod