megaZ

My 260 keeps dieing whenever the brakes are applied. Even when idling it lowers the rpms and dies. Does anyome know why? Ive looked it up and said its the brake booster, does anyone know any good upgrades from differnt nissains, or any way to fix it

zxguy1986

Welcome to ZDriver!

Be sure to pick up a free factory service manual at XenonS30. Lots of other cool docs there too - all of which will be useful in keeping that Z on the road. Check out the inspection and troubleshooting sections in the FSM - which are easy to understand and follow.

Our 260 pros will be right with you. Sounds like an electrical issue to me - but let's see what the pros have to say.

Thanks and welcome!

Steve260Z74

Where did you read that the brake booster would cause that problem? I'm curious.

Of course, to verify, remove the vacuum line from the intake manifold, and plug it on the manifold. See if it idles properly, etc. Don't drive it like this, though.

megaZ

I read it on one of these forums, it talked about there being a leak and making sure the check valves werent stuck open. But others said it could be a fuel pump or fuel leak. I am at a total lost about the situation but would really like some help, i havent been able to drive it for a while now and just to fix it.

Steve260Z74

Okay, so there is a lot of information missing.
Do you have round top or flat top carburetors?
Have you made sure your carburetors and timing have been adjusted per the FSM?
Have you inspected vacuum lines for leaks? (I'm having to replace the line to the check valve myself. The new one arrived yesterday.)
What is the voltage at the battery when the car is idling?
What do your spark plugs look like?
How old is your coil?
Are you still using the stock ignition (Transistor Ignition Unit)?
Is the rotor in good shape?

That should keep you busy for a while. Good diagnostics leads to better solutions (and less money spent on repairs).
Don't forget to look at the troubleshooting guides in the FSM, too.

FrappNasty

There should be a one way check valve leading from a line on the brake booster. This allows regulated vacuum flow to the booster. Also check all vacuum lines. I spray brake clean while the car is running around lines, intakes etc, anything the is exposed to vacuum. If you have a obvious leak, the engine will sputter or change idle quickly. Just watch your eyebrows...