People Seeking Info

You are not currently logged in

Locating and Repairing Fuel Leaks:

If the smell of fuel comes from the air vents it's probably originating from the fuel damper, fuel pressure regulator or loose interconnecting hoses. Other parts could be at fault such as the fuel filter connections or fuel injectors.


This is a combination of my experience and what I've read from the service manual. I am not a mechanic, don't come running to me if your 300 turns into a barbecue. Observe all standard safety practices for dealing with gasoline (flammable) in this type of environment.


Fuel smells will usually start during colder weather, since the parts contract even more in the cold air during a thermal cycle. Hose clamps often work loose. When a fuel smell is noticed inside the car, examine it ASAP, there is an EXTREME DANGER of a car fire starting. This is no way to loose a perfectly good car.


I ordered the hoses from Courtesy Nissan. To replace all the connecting rubber hoses to/from the damper and regulator you will need about 12 inches of fuel line, I ordered 15. Check exact amounts before you order. (always re-check the part numbers, I'm a UK driver!)

1. Fuel regulator assembly (part 2267010Y00, approx. $50)
2. Fuel damper assembly (part 2267510Y00, approx. $50)
3. High pressure fuel hose � 15 inches (part 8959080, approx. $15)
4. Protected fuel hose (part 1644030P11, approx. $40)

The fuel pressure regulator (1.) keeps the pressure in the fuel system (including the fuel tank) at 43.4psi., so the cylinders can get enough fuel when throttle is applied. It takes some of the pressure built up in the manifold to increase the fuel pressure.

The fuel damper (2.) fits between the fuel filter and injectors. It reduces the pulsation caused by the fuel pump, which is back in the fuel tank.


1. Check the fuel hose clamps from the devices indicated in the pictures, making sure they are tight.

2. Look for visual signs of discoloration around the fuel damper and regulator on the hoses.

3. Try putting just a little talcum powder around the hose where it connects to the devices. Check after starting from cold and warming the car up to see if it looks damp. If so, that's the faulty part.

4. If a part is found or suspected to be faulty, replace the connecting hoses as well.

5. The 'protected' fuel hose (2.) exiting the fuel damper (to the right) is a special part, it doesn't come from a roll of hose.


1. Always use Nissan 300zx high-pressure fuel hose, anything else could be very dangerous.

2. Always relieve the fuel pressure when working with these parts. The procedure is illustrated on

3. Always expect some fuel to spurt out when you disconnect a part, even after relieving fuel pressure.


Back to Tech page

1.Fuel pressure regulator
2.Fuel damper and 'protected' fuel hose