Questions - fuel lines and tacho

[BobsYourUncle]

Hi everyone, I'm back with some more newbie questions that I feel embarrassed to ask. (Amazon are predicting my repair manual and restoration book won't arrive until late next month, I should've paid more and got them locally )

 

1) I've got quite a strong petrol smell in the car under acceleration. First thought is it's running rich and I need to adjust the carbies, but a forum search suggests it could be a leaky fuel return hose. My questions is, where is the fuel return hose?

 

2) My tacho isn't working, but I have seen some movement from the needle when I tried to start the engine a while ago, making me think the tacho itself could be ok, so I want to check the engine bay connection for it before I dismantle the dash to get to the tacho. Problem is, I don't know where and what it connects to?

[xa1973]

 

There will be a fuel canister in your engine bay with a return on it ( as pictured )

 

You can trace this back, however I would be more inclined to replace all your hoses, filter etc, a quick way to check for system leaks, a helper is good for this, start your car when its cold run it for a few seconds only, turn it off and look for the wet spots ( no pun intended )

 

Check all your electrical connectors for your tacho, they corrode over time, may just need a quick sand

[Zedman240®]

For the tacho, connections are on the coil. Don't forget the tacho's on zeds are "+"ve triggered. Check all the spade connectors and make sure they are firmly on. I've seen connectors that look fine but were broken internally!

[sexual_sushi]

check all your lines first, it's the easiest first step and it probably is your fuel lines. I had a crack in one of my fuel lines and you could actually see it spraying out form the hose when the car was revving.  But if this isn't the problem, it could also be:

 

1. Floats in the carbies. Alan on here has a really bad problem with his carbs and has fuel pooling in his airfilter housing. We haven't fixed it yet but after watching z therapies SU Videos I think it is because the floats aren't set correctly, which lets extra fuel in. This then seeps out a hose into the air filter housing. To fix this correctly you have to readjust the float. You can remove the gasket on the fuel bowl which will let the fuel just drain out from there which might be slightly, but not much, safer then the fuel pooling above the exhaust manifold. This is assuming you have SU's and all the original piping etc on it

 

2. Unlikely but it could be the fuel filler neck. The plastic/rubber in these go hard over the years and crack. Quite common but you'd notice it more when you filled up not under acceleration like you said your problem was.

[RB30X]

Isn't that a charcoal canister in the pic above??

 

Your return hose is 1/4" or 6mm vs your supply from tank which is 8mm or 5/16".

[stevo_gj]

In my Z the fuel return line doesn't go to the carbon cannister it goes to the fuel tank  Might be different in others though..