I have a stupid question re: injectors - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Jorge18 · 07-24-2015, 02:09 PM

I'm having some issues with my car running very rich and my pistons flooding with fuel. I've read on here repeatedly that it could be that one of my injector O ring could be bad.

Maybe I'm being stupid, but I can't figure out how a bad o ring would cause the car to run as rich as it's running (10 AFR)

Can anyone explain this to me?

ultimateirving · 07-24-2015, 04:25 PM

the Oring is a gasket in essence. If it's ripped or missing it will leak fuel right into the Intake.

kane01 · 07-24-2015, 11:09 PM

Not sure about the o ring thing. Unless its inside the injector. Injector not sealing is gonna be a lean situation as in vac leak or fuel spewing out of fuel rail. Sounds like you have a wideband which helps. Is it always pegged on 10? I had RC knockoffs that were way off on resistance and had the same problem. They were too open for too long. What mods are you using ( engine wise )?

From your moms basement / using hacked rotary phone

blkvrtswp · 07-25-2015, 09:04 AM

Fuel leaks past the lower O-ring and around the injector body directly into the cylinder rather than being metered thru the injector. It doesn't leak externally.

External leaks are usually from bent fuel rail, bad manifold spacers, wrong or incorrectly seated upper O-rings.

kane01 · 07-25-2015, 01:37 PM

The injector only gets a certain amount of fuel. Either it goes through injector at the correct rate when it pulses or it does not. Fuel not going through the injector and you have a missfire and possibly a real fire if its a bad leak. We are talking about top feed injectors right. Fuel going past an oring isnt going in your engine, its going there when the oring is not leaking. Without knowing mods check your resistance on injectors. No disrespect on the oring thing, if thats what it is you'll save a ton of money.

Kingtal0n · 07-25-2015, 01:54 PM

pull the rail out and run the pump. Leaks will become obvious.

cotbu · 07-25-2015, 03:13 PM

Quote:

Originally Posted by Omega

btw pics?
damage? cracks? warping? chips? etc

You tried to redeem yourself but....:thumbdown:
Any fuel leaking externally from a top feed injector should be obvious.

Sent from a Highly Tuned Note 4.5!!!

blkvrtswp · 07-25-2015, 03:13 PM

Quote:

Originally Posted by kane01

We are talking about top feed injectors right.

Although OP didn't specify, stock SR and KA injectors are side-feed. On side-feed when the lower O-ring is leaking the fuel goes straight into the engine.

You are right with top feed - you see the leak externally.

kane01 · 07-25-2015, 03:34 PM

There is an s on on the end of the word piston in his comment. That screams wrong injectors. Do all of the stock ORINGS go bad at the same time, why does anyone use them at all then. Anyway, good luck with your issue. If you changed anything lately prior to the problem(like all your injectors) i would start with checking resistance, need to know how old injectors are functioning anyway.

07-24-2015, 02:09 PM	#1
Jorge18 Leaky Injector Join Date: May 2007 Location: Miami Age: 35 Posts: 58 Trader Rating: (0) Feedback Score: 0 reviews	I have a stupid question re: injectors I'm having some issues with my car running very rich and my pistons flooding with fuel. I've read on here repeatedly that it could be that one of my injector O ring could be bad. Maybe I'm being stupid, but I can't figure out how a bad o ring would cause the car to run as rich as it's running (10 AFR) Can anyone explain this to me?

07-24-2015, 04:25 PM	#2
ultimateirving Zilvia FREAK! Join Date: Nov 2010 Location: arizona Age: 33 Posts: 1,519 Trader Rating: (1) Feedback Score: 1 reviews	the Oring is a gasket in essence. If it's ripped or missing it will leak fuel right into the Intake. __________________ Z32 with lq4 swap Desert Street Scene \|\| Dssevents.com

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07-24-2015, 11:09 PM	#3
kane01 Join Date: Jul 2015 Location: Mid Mo. Age: 47 Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	Not sure about the o ring thing. Unless its inside the injector. Injector not sealing is gonna be a lean situation as in vac leak or fuel spewing out of fuel rail. Sounds like you have a wideband which helps. Is it always pegged on 10? I had RC knockoffs that were way off on resistance and had the same problem. They were too open for too long. What mods are you using ( engine wise )? From your moms basement / using hacked rotary phone

07-25-2015, 09:04 AM	#4
blkvrtswp Zilvia Addict Join Date: Oct 2012 Location: NY Posts: 691 Trader Rating: (9) Feedback Score: 9 reviews	Fuel leaks past the lower O-ring and around the injector body directly into the cylinder rather than being metered thru the injector. It doesn't leak externally. External leaks are usually from bent fuel rail, bad manifold spacers, wrong or incorrectly seated upper O-rings.

07-25-2015, 01:37 PM	#5
kane01 Join Date: Jul 2015 Location: Mid Mo. Age: 47 Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	The injector only gets a certain amount of fuel. Either it goes through injector at the correct rate when it pulses or it does not. Fuel not going through the injector and you have a missfire and possibly a real fire if its a bad leak. We are talking about top feed injectors right. Fuel going past an oring isnt going in your engine, its going there when the oring is not leaking. Without knowing mods check your resistance on injectors. No disrespect on the oring thing, if thats what it is you'll save a ton of money.

07-25-2015, 01:54 PM	#6
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,646 Trader Rating: (17) Feedback Score: 17 reviews	pull the rail out and run the pump. Leaks will become obvious.

07-25-2015, 03:34 PM	#9
kane01 Join Date: Jul 2015 Location: Mid Mo. Age: 47 Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	There is an s on on the end of the word piston in his comment. That screams wrong injectors. Do all of the stock ORINGS go bad at the same time, why does anyone use them at all then. Anyway, good luck with your issue. If you changed anything lately prior to the problem(like all your injectors) i would start with checking resistance, need to know how old injectors are functioning anyway.