2003 cavalier hard to start
 

I think this one will take some thought. This is not my car so I do not know intimately what, if anything led up to this. Here goes. Car dies on them while driving in town. Won't restart. (All of the following no start conditions are that it cranks over good and strong but will not fire.) They tow it home. They call me to fix it, I go the next day and try it and it starts right up. Pretty hard to troubleshoot a problem that isn't there. They drive it for a week more with a few instances of the car won't restart after shopping in a store, but if they wait a few minutes it sometimes starts, sometimes no. But it will usually start the next day, but not always. So now it is worse and only starts very infrequently. It seems so random though.

I read on the internet about these cars being notorious for loosing fuel pumps, so I check it out. There is a buzz in the fuel tank when I turn on the key, but I am not convinced, so I replace the fuel filter and while I have it off I check that the pump at least moves fuel by turning on the key while the hose is disconnected. Gas squirts out happily. Back together, no start still. I check for spark, there is spark. So I remove the intake ducting and shoot in some ether while someone else cranks the starter and VIOLA! starts right up. So I say, it isn't getting good fuel pressure. So with what I have read about the fuel pumps in these being crappy, I drop the tank and replace it. Oops! same problem still there. No start. Cranks over fine. It starts and runs after a shot of ether.

This is where I want a few expert opinions. I have thought of vacuum leak. I looked for one visually and used the old method of shooting carb cleaner all over the intake manifold and its fittings and listening for a change in idle speed or quality, but found nothing. That is another strange thing to me. Once it starts, it runs smooth and has plenty of power as your driving. There is nothing to indicate that anything is wrong. No CEL. I don't want to just throw parts at this thing, I feel a little like I have done that already even though my decision-making process was (I believe) sound. What is it? Fuel pressure regulator? Some sensor? The injectors? But if it is the injectors or a sensor, why would it run fine after ether gets is going? Please help.

It's me again
 

Okay, I can get it to start by doing the following: Key to on position for 2 seconds, off for an instant, on for 2 seconds, off for an instant, on for 2 seconds, off for an instant, on for 2 seconds, start position and Viola! it starts. Here's how I see it happening. Instead of getting only 3 seconds of priming before starting (which is the usual amount the fuel pump stays on before it shuts off), I am giving it 8 or 10 seconds of essentially unbroken priming by doing the above key acrobatics and therefor overcoming a bad fuel pressure regulator by building pressure faster than it can leak it off. This gives it sufficient fuel pressure for start up. What do you think?

Sounds like it could very well be a regulator issue, or perhaps it jumped time? What engine does it have? 2.2 OHV or 2.2 OHC? Have you tried to hit the accelerate a bit while cranking it over to see if that allows it to fire up?

no start
 

Ignition switches are bad on these cars and your symptom's sound like it