Recently my '93 z28 has had trouble starting. I'll turn the key to the on position and the dash lights come on and I hear the fuel pump whir, but when I go to start, it won't turn over. Eventually I can catch it where it just barely beings to start, then I give it a little gas and it comes to life. I hold it to 1500rpms for a few seconds, then it idles fine.

What could be possible causes?

I should mention that before this began happening, I noticed my car would seem to get "quiet" when I came to a complete stop. It almost sounds like it goes quiet, something "clicks" then the quiet goes away.

TIA.

 

Explain turn over. Do you mean it won't rotate the engine or do you mean it rotates but doesn't fire?

If it rotates but doesn't fire, I would look at your fuel pressure when the car is shut down. Get a fuel pressure gage if you don't already have one. Get the kind with a hose. The shorties are almost useless. The fuel pressure should hold for quite a long while (a day or more). If the pressure bleeds off after the car is shut down then you need to check a couple of things. 3 things can make the pressure bleed down. Leaky injectors, a hole in the fuel pressure diaphragm or a stuck check ball in the fuel pump. Your problem seems as though the engine is flooded when it starts so only 2 of them could cause that.

Start by checking the vac line connected to the fuel pressure regulator. See if it's wet when you take it off the regulator. connect a hose to the regulator and put a vacuum on it and see if it holds. If it's wet or doesn't hold vacuum, replace the fuel pressure regulator.

If the regulator is ok but the pressure bleeds down, the next thing to check are the injectors. This is a bit of a pain. You will have to remove the injector rails and lift all the injectors out of the intake while still connected to the fuel rails. While lifted up, you have to turn the key to the on position but not start and look for injectors that are leaking. Instead of doing that, I would have someone professionally clean the injectors through the fuel rail. I use 3m cleaner and love it.

I hope this helps and let us know how you make out or what you find if still have trouble.

 

When I say turn over, the car barely starts to fire, then dies. This is how I get it to start; when I hear it barely start to fire, I give it a little gas and it comes to life. Does this narrow down the list of possiblities a little?

 

See above post

 

I have noticed that the problem seems to happen when it is cold outside. Could these fuel problems be affected by the cold weather?

 

93RedDevil,I seem to have this same problem, you fix it?

 

Well, I haven't solved it, but I found that running some injector cleaner through helped out a lot. I've only had it happen once now in the past month and a half. I know it's nothing with the fuel pump or regulator and it's not the computer. So I myself am still puzzled.

 

Could be idle control valve needs cleaning,or the wires leading up to it could be toast.Hope this helps.(The brass looking thing on the left side of the throttle body.)Take the bellows off,spray ever so gently inro that tiny hole on the bottom of the throttle body,put the belows back on,see if that helps.Hope this helps.