Is plumbing solder suitable for repairing a cracked joint on a efi fuel rail

Silver solder is better, but I've used plumbing solder in the past and it's worked fine. It is quite soft though.

I wouldn't trust it considering the implications of a fuel railing failing. I'd want to go for brazing or (at a push) silver solder....

Just use silver solder/braze and the proper flux as the flux for plumbers solder is as good as a barrier for silver solder to stick to in my experience

First went with plumbers solder and flux on mine and it just wasn't up to the task and was damned dangerous as it would keep weeping and cracking

Took it to several places to get it re done and it was always a disaster and it would crack at the joins and it just wasn't sticking no matter how much emery cloth, flux and heat were used

I got a burner myself (Lidls special- and a big bottle of butane) and remade the joiners (brass) and made sure all traces of old solder/flux was gone from inside the rail and silver soldered it myself with the proper flux, no leaks or cracks since

Are you pipes just butted up to each other?

I made some joiners that butted up externally, but had tails that slide inside the original rail

Pic of the joiners I made attached

Regards
Rob
Rescued attachment fuel rail joiners .GIF