# Fuel injector O rings potentially gone bad



## ommynous (Aug 23, 2016)

Lately, I've been noticing a random smell of gas. It's usually after I start the car, but not every time. Well the other day, I filled up my '02 sentra GXE, to 3/4 of the way, and after driving about 95 miles, 80 of which were interstate, I burned through half a tank of gas! The whole time, smelling of gas. Not very strongly. It also smelled of gasoline after we got off the interstate, where it was just my car around. So I know it wasn't traffic.

I've also had problems with the vehicle running rich. Drowning my spark plugs(once), and fouling my coil packs it seems. I've had to replace 2 in the last year, and the issue doesn't go away. Last I checked, I only had 3 CEL codes.

The exact codes at the time were 

P0127 Intake air temperature sensor
P0300B - misfire
P0328 - knock sensor 1

Is it possible for the fuel injector O rings to go bad and leak down into the cylinder? The one time my car wouldn't start, I took the plugs off, dried em up, and the car started for me immediately - with a noticeable smell of gas. When I took the plug out of Cyl #3 (going from left to right) There was a visible gas vapor. I replaced all the spark plugs and that coil pack the following weekend.

What could it be? I know the IAT can cause rich running, and I know my ECTS is going out - my temp gauge on my dash board hasn't been on in weeks, except for driving at night. Could those 2 be causing it to run terribly rich and have a gas smell?

I'm almost at my wits end. And no, I haven't noticed or seen a single leak in the tank, fuel lines, or anything. I get decent gas mileage as well.


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## Skanlig (Dec 9, 2016)

How did you decide this?


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## rogoman (Dec 16, 2004)

ommynous said:


> Lately, I've been noticing a random smell of gas. It's usually after I start the car, but not every time. Well the other day, I filled up my '02 sentra GXE, to 3/4 of the way, and after driving about 95 miles, 80 of which were interstate, I burned through half a tank of gas! The whole time, smelling of gas. Not very strongly. It also smelled of gasoline after we got off the interstate, where it was just my car around. So I know it wasn't traffic.
> 
> I've also had problems with the vehicle running rich. Drowning my spark plugs(once), and fouling my coil packs it seems. I've had to replace 2 in the last year, and the issue doesn't go away. Last I checked, I only had 3 CEL codes.
> 
> ...


There are 2 O-rings per injector. If the bottom O-ring is bad, it won't cause fuel flooding just create a vacuum leak. However if the top O-ring is leaking, you'll see a lot of raw fuel around the outside of the injector. If the cylinder is getting flooded, it's caused by an internal injector leak, meaning the inside of the injector has gone bad or has lots of dirt inside of it. To test for a leaking injector, install a temporary fuel pressure gauge. Now turn the ignition key to the run position but DO NOT START THE ENGINE. It should hold the pressure for a long time. However if it drops off rather quickly, then there is one or more leaking injectors.


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