Injector o-ring size

WankelsRevenge · 02-12-2014, 04:04 PM

Went to drive my car today only to find out its pissing out fuel everywhere. I think on of the o-rings on one of my fuel injectors piped and is t sealing right. Does anyone know what size o-rings I need to get? I figure I might as well do all four while I'm at it to solve future problems ahead of time.

RETed · 02-12-2014, 05:09 PM

They are not some standard size.
I tried sizing them through McMaster-Carr, and none of the stuff they had listed worked.
I just used to pull good, used ones from old injectors...

Also, all of the 80's Japan cars (i.e. Toyota Supra, Corolla) will all work.

-Ted

Pete_89T2 · 02-12-2014, 06:14 PM

Since the OP said he found his car pissing fuel AFTER going for a drive, in the interest of preventing another FC car-b-que, I'll mention that it's pretty easy to pressure test the fuel system after installing injectors but before you put the UIM & rest of the engine back together...

I know this is the case for S5 T2's & NA's but it probably applies to S4s as well. Look for a yellow 2 pin connector plug by the passenger side shock tower. Put a jumper across its 2 terminals, and switch the ignition to ON (not start, duh). You'll hear the fuel pump running, the fuel system pressurizes and you'll know quick if you have a leak. Here's the FSM section for more details:

WankelsRevenge · 02-13-2014, 01:40 PM

So turns out it was the pulsation dampner. Ive heard about replacing it with a banjo bolt, anyone know any more details about how to do this? Also discovered one of the connectors to one of my fuel injectors was broke, so instead of just replacing that, megasquirt here i come!

RETed · 02-13-2014, 01:48 PM

http://fc3spro.com/TECH/FAQ/pd.html

Part numbers might not work though...

I can confirm that using the check connector suggested by Pete_89T2 will work for all FC's.
Specific to the S4, it bypasses the fuel-pump cut-off switch located in the flapper-door AFM, so it triggers the fuel pump on with the key in the ON or START positions.
I believe it's similar to the cone-type AFM for the S5's.

-Ted

WankelsRevenge · 02-13-2014, 02:41 PM

O yeah that deff worked. I had the plug jumped before I keyed the ignition and had gas spraying everywhere. I pulled all the fuel injectors though and all the O-rings looked in perfect condition, though Ill probably change them anyway. Hoping to get my megasquirt setup and installed within a few weeks. Also ordered a set of AEM wideband and water temp gauges while I was at it so Ill have some fun planned in the future.