Trouble starting the engine on the hot day.

[Ken Lis]

Hi, guys.

In the morning my Z starts fine before I went to work. Or on cold day it start up fine, but in the heat of the day in the after noon, my Z have a hard time firing up. I crank it many times and it would not fire up. It seem like that there is no fuel coming in to fire up. I checked everything including fuel line, Cap and rotor, spark plug and wires, gas fuel filter and so on. Everything is fine.

It has been like this since I put in the new starter to the motor. And I modified the ignition a little by short cut the hot wire and line it to the starter.

Any suggestion why is happening like this? I'm open for suggestion.

Ken

[Ramius83]

This could be the indication of a failing fuel pump and/or faulty fuel pressure regulator.

If it is the fuel pump, it will sometimes be an intermittent problem, then it will eventually fail.

In regards to the fuel pressure regulator. It is supposed to hold the normal fuel pressure over a certain period of time. If it is faulty, it could be releasing all of the fuel pressure over night or even instantly. Then, when you go to start the vehicle, the fuel pump has to build that pressure back up before it can start.

Just two possible causes. But to diagnose both, you will need a fuel pressure gauge hooked up.

[Ken Lis]

Yes, I replaced the fuel pump and it's still doing the same thing. Now that the next I'm going to do is change the Fuel presure regulator to see if it working or not.

To start the engine I have to open the valve on the intake and shoot some carburator cleaner solution in to get it start.

What do you think? Fuel presure regulator.