After two months of frustrating weekends, missing parts, etc, the 406 finally ran in the car. It was almost a no-go, as we discovered I had a bad fuel pump- at least I think. Disconnected line from the carb, it wouldn't pull any fuel when cranking. However, when we disconnected the line at the bottom of the tank, it wouldn't even drip. Blowing air INTO the tank was no problem- it bubbled fine. Its a brand new tank, with old hardware (that had been acid dipped before reinstallation) and new hose. Is this normal?

Anyway, no one in three towns neighboring my small town had that pump!!! I got an electric and put in inside the frame next to the tank- worked great. The only thing now is.... this is just a single pressurized line going forward. The smaller line next to the main one is no longer being used. What is this line for? Can I leave it disconnected?

One more thing. The air cleaner has about a 1" short hose coming out the bottom from inside the filter. My new valve covers also came with what I think is a PCV valve and braided hose, only about 3/8". Do these connect together? What is the PCV valve for? Is it necessary?

It ran great, and very few addl problems surfaced once running- I was amazed! I even got to test the posi on the driveway


Thanks for the help!
-=Boston!=-

 

Ya definetely keep the PCV valve. It will make your engine last longer and is good for emissions too with no performance loss. The PCV valve is usually in the drivers side valve cover and connects via a hose to the front of the carb. The hose you talk about sounds like the breather hose which normally connects to the hole in the valve cover on the passengers side. You have a big round chrome breather in yours so you can just plug that 1" hose.

 

Thanks Boofers! That front port on the carb is now connected to a line that leads off under the drivers fender..... I'll have to check where it goes.

Anyone have a word on the second fuel line? I'm just planning on leaving it disconnected and putting a plate over the fuel pump boss on the block. Also the tank: should no fuel drain when the line is disconnected?

-=Boston!=-

 

Congrats on the new motor, looks like a real sleeper, you might want to loose the fancy top rad hose, paint the valve covers blue and make a few bucks at the track

 

ttt

 

The second line is the return line to the tank for overflow. The original pumps pumped fuel to the carb and the excess was returned to the tank via that extra line.

If you are running a regulator to keep the pressure constant, the return line could be re-used. If your setup doesn't have a regulator, then I guess you just don't use it. If you don't use it, you will need to make sure your tank is vented, or you won't get sufficient fuel to the engine.

The fuel drainage would depend on whether the tank is vented or not. If the tank is completely sealed, there will only be a dribble from the line. If the tank is vented, gas will pour out of the line.

 

Thanks, Z-man. Is there a reason I should worry about keeping the psi constant, or can I just let the electric pump run? In any case, I'll leave the second line open in the engine compartment (with a filter) to vent the tank.

The cap was off the tank when I was watching for fuel to drain, and it wasn't even dripping. Do I need to take the bottom tank assy out and check for plugs?

-=Boston!=-

 

I had to plug mine.

Mine was leaking quite a bit of fuel.

 

ttt