98 Z, ls1, 80k miles.
Turn on the key, and let it sit in the on position for a few seconds, it will normally start the first time, but not always. It is less likely to start the first time if you just go straight from off to start, but i would ballpark it at 50% normal starts. sometimes it stutters, and then fires up. Once its running, it appears to run completely normal.
I havent done anything with the fuel system in some time. I am trying to remember if I replaced the fuel filter, but if I had, it would have been about 10k miles ago, in wich case, one would think it would still be ok.

Plugs & wires?
any ideas?
im actually on a buisness trip this week, so I wont be able to look at the car to answer any questions, but if there is any information I am forgetting to say, please ask.
thanks in advance.

 

check fuel pressure, have the injectors been cleaned. Is the SES light on.

 

I'd check fuel pressure first, then replace the fuel filter and see if there's any change.

 

ses is not on, and I haven't specifically cleaned theinkectors, but I did seafoam it a few months ago. if I remember correctly, it was doing this prior to that.
how would I go about checking fuel pressure? if its low, I'm guessing I am looking at a new fuel pump?

 

there should be a spot on the fuel rail somewhere that looks like a air valve on a wheel or inner tube. Use a fuel pressure gage that will connect to that. I don't know what the pressure should be. I will try to look it up and let you know.

 

1998 ls1 does not have a return so the fuel pressure should be between 55 and 60 psi. 58psi is what I have found in most publications