The last injector on the fuel rail is leaking fuel under full boost only. Not a lot but it should be fixed. I'm guessing Ralliart also has a returnless system. It's not an emergency cause they're working fine on regular driving. Any ideas what to do?

 

do you have an aftermarket pump? I don't remember more pressure=more leaking.

either replace the o-rings or if you had to customize the fuel rail to get it bolted down with the aftermarket injectors you could have either too much pressure or not enough pressure on the o-rings to seal properly. too much pressure and they will bind, too little and... well that's obvious.

 

Replace the o-rings and make sure they're properly seating in the rail. If it's leaking form the rail, the o-ring is bad, and the excessive fuel pressure at full boost is overcoming the seal of the o-ring.

 

Make sure you put some oil or silicone grease on the o-ring, before installing. Your lucky it's the last one, should be easier to replace. Good luck!

 

IIRC.....aftermarket pump and stock fuel rail?
+1 on o-rings.

 

The fuel pump is stock. It shows that it's more than capable of supplying enough fuel. I have an Evo 9 pump I was gonna put in, but it might not be necessary. Is the Ralliart returnless also? Does it have to be converted to return, or are the o rings enough?

 

RA is returnless yes.

 

Definately sounds more like an o-ring or injector seating problems. Make sure you tight them firmly and BTW what size injectors you got? For returnless system I recomend running at least 500cc's.

 

I'm using the stock fuel pump and my injectors are 550 cc DSM ones.

 

stock pump, rail, and aftermarket injectors? did you have to customize the rail at all to get them to fit? using wrx injectors you would have to make the rail mount further away, for instance. if you needed to finagle something that is most assuredly where your problem is starting. after checking the condition of the o-rings I would start checking my fitment.

 

I'm gonna have to talk to the guy that did my turbo. He'll know what he did and how to fix it.

 

I'm sure it's a combination of things that lead to an already failing seal to break.
I think your best bet is to just put new o-rings on. It's really not that difficult and it'll prevent an engine bay fire. Any gas leak within the engine bay is serious for obvious reasons. There are several flash points under the hood of a car that could ignite gas vapors and leaks.

 

Thanx for the info guys.

 

Good luck.

 

Ok guys, it's fixed. We had to put a different washer on and tighten it up a bit. No leak under boost. And the engine doesn't shake anymore when idling either. I guess there was a bit of air leak around the injector.