I am trying to diagnose what could be causing a faint smell of gas from my 2002 4.7L Dodge Dakota whenever I am using the heater/AC using the fresh air setting. This happened just over a week after replacing the spark plugs with NGK V-Power plugs over the summer. It is noticeable whenever I am stopped at a light or stuck in traffic and the smell is even stronger when reversing (i.e. backing into a parking stall).

I put a jumper wire in place of the fuel pump relay and found a small gas puddle accumulating on top of the electrical connector on top of injector. This led me to replace all eight fuel injector o-rings, which didn’t help. I did apply dish soap to each o-ring, but I stupidly wiped the rings off pre-install to ensure that they went in clean. I wanted to rule out the o-rings, so I pulled the rail and the injectors and reapplied dish soap to the o-rings. After driving it for two weeks, the smell has defiantly improved as it is not as strong as it once was, however it is still there.

I also did a leak test on the fuel rail by sealing up the holes and dipped it in water and saw no air bubbles, so I don’t think it is coming from the fuel rail.

Could I have shoddy o-rings? I put the jumper wire back on and there is no longer any leaks which tells me no. The only other thing I could think of is there could be a trace leak coming from the quick connect fitting from the fuel hose that goes from the gas tank to the rail. However, I am open to any suggestions at this point as I just want to get this fixed.

 

Dang that sucks. The O-Rings sounds like it would have taken care of it. If you haven't already I would suggest fully washing out the engine bay. Then double check it. I know they have UV detector kits for oil and coolant. But I don't know about fuel. But Check around and see if you can find one. That will be the quickest way.