1985 Nissan Motorhome

[Mick Thompson]

I have a gas leak at the side rail frame, a carb with a electric pump. The z24 runs great but after driving around the block with a full tank it leaks a lot when I park and idle. When I turn the key to the start position and not running there is no leak.

[datzenmike]

It just means the pump is on when leaking. Could also be the return line????

[Mick Thompson]

What else could it be besides the return line? That electric pump has a internal filter, where can I get that filter and also a new ignition key lock cylinder ? Thanks.

[datzenmike]

If it's gas then there are only to the carburetor (under about 3PSI) and the return (pretty much no pressure) back. Both will have gas when the electric pump is running.

 

There should be an in line filter between tank and pump so the internal one doesn't get that dirty. There is also a magnet in the bottom of the screw off cap on the pump. I think Tommy on here knows about the filter. He'll be along.

[Mick Thompson]

No word from Tommy yet. Now I have found a Fuel pump relay, what does it do and if it was not working right what would it affect ? Thanks

[datzenmike]

It not working properly anything from failure to start to starting but quits a minute later. It's sole purpose is to turn off the pump in the event the engine stalls for any reason, including an accident. The last thing you want is the pump pushing gas to the engine and the line is broken or there's a fire and you are hurt and can't reach the key.

 

I think the ON of the ignition starts the pump but on timer and will shut off in 15-20 seconds. It's assumed the engine will start and this will provide two other inputs that will keep it running. A charging alternator is one and oil pressure is the other.  Soif engine stalls no charge and no oil pressure the pump timer times out an no fuel.