Walbro 400 fuel pump melting factory plug.
 

So i have a walbro 400 and it is constantly melting the plug at the connection and I cannot figure out what to do to fix it. I am running a direct power line (10ga) with a 30/40 relay and 30amp fuse from battery and have pinned a 10ga ground wire into the factory plug. I have tried directly pinning the wire to the plug, melted the plug.:52: I have tried connecting it to the factory wire, melted the plug.:52: I have tried pinning a 14ga wire and connecting the 10ga wire to that (trying to reduce resistance) and still melted it.:52: At this point all i can think of doing is drilling through the top of the basket and running a wire directly to the pump and sealing it with epoxy, but I'd rather not have to do that as there is no coming back from that should I want to return to stock.

Google searches pull up quite a few others that have had this issue but none of them have had the exact same problem, or if they did, it did not appear that they resolved it.


Anyone here running the walbro 400 having this issue?

Will be running it, subbed goodluck

Obviously that pump is drawing too much current if it is melting the plug

Perhaps it is defective?

Why not try an OEM pump?

Telcoman

Oem pumps are only good for oem power tho

Yeah, I can't exactly use an oem pump to supply 1000cc injectors and a full fuel return setup for my single turbo.

The weird thing about it is I ran this pump with the 10ga wire connected to the factory wire for 4 months with no issue and then one day I found it melted and now I can't get any setup to last more than a week.

Might just have to bite the bullet and hard wire it straight to the pump, but if it's something else, I don't exactly want heat melting current going trough my gas tank haha.

Everything has been triple checked. And the weird thing is, I have the exact same wiring and relay setup used to power my oil scavenge pump, but those wires never get anywhere close to hot so I'm thinking something is going on with the factory pin setup?

Shorted windings in the pump?

Measure the resistance of the pump winding/coil and compare with another one or factory specs

Telcoman

I'm certain it isn't a pump issue. Having a short like that would cause my car to run lean. An issue like that would cause too much voltage loss to supply the fuel system. I do think you're on to something though. I'll check voltage levels all the way from the battery to the pump and see what i find.

Mind you, the melting is happening where the factory plug meets the basket at the pins. I checked to see for any heat or damage with the in tank wiring and everything is still perfect. Pump is still healthy and keeping up with all my needs. ( not an old pump by any means either)

Buddy with a 240sx came over with his walbro 400, both draw the same amps in case anyone is wondering about it being a pump issue.

Currently checking the factory soder points to make sure that isn't the issue

Yeah on my Turbo 1995 240sx I'm running a 400Lph on it also with the stock/oe pump plug and I made a custom subharness for my relay that I added,runs like a champ for 4 years now

So it's not the factory solder points. I guess the small factory pin just cant handle the amp draw of the pump and that is the smallest point of the whole setup so it creates a ton of resistance and melts anything near it.

I just find it strange that I have not heard of anyone else having this issue with their Zs and Gs. Or maybe they just have not posted about it haha.

Anyway, gunna run a direct power wire, drill through the top of the assembly and epoxy it, and buy a spare fuel basket assembly, they're only like 70$ now a days anyway


https://cimg1.ibsrv.net/gimg/g35driv...b66000b24e.jpg

https://cimg2.ibsrv.net/gimg/g35driv...79bd36673f.jpg

Ended up buying a brand new oem fuel assembly and havn't had a problem since. Must have been poor solder connection in the factory assembly.