I have been creepin this forum for quite some time. I have read a lot of threads about misfires and not wanting to start. Thanks to this site I have found some good things to try and a lot of info. I am about to pull my hair out trying to figure out what is going on.

The car has 175k mi. On it's 2nd trans.

The problem is when the car is warm and making multiple stops (shutting the car off and on) it gets hard to start. It will not want to start and it does it runs really rough. You have to keep your foot on the gas to keep it from dying after you get it started. After a while it will run smooth again. It never randomly misfires or runs bad other than this warm start issue. It will give a misfire codes after not wanting to start sometimes.

I have cleaned the egr ports, and I have replaced the main relay. What else can I try? Replace the egr valve? Push it off a cliff?

 

try testing your coil packs. With your car idling pull the connector to each coil pack one by one. If your engine sounds different when you pull one, the pack is good. Plug it back in and move on to the next. If nothing changes when you pull a connector, That's your bad pack.

 

I had a coil pack go out on me a couple years ago. It would run rough all the time and it was obvious that it was a missing cylinder. I used this method to determine what coil was bad.

This problem is only on warm starts with multiple off and ons. And really hard to simulate, like always somewhere inconvenient.

 

I had this same issue, it was the fuel pressure regulator for me. Replaced it and problem went away completely.

You hit it on the spot with the keeping the gas peddle pressed to prevent the engine from shutting off. It is because the engine is running too rich since the gas isn't being routed back to the gas tank fast enough, causing high fuel pressure and the injectors are shooting too much gas into the combustion chamber. A bad fuel pressure regulator will clog up overtime or the rubber diaphragm inside it leaks/rips. Do you smell excessive gasoline when you're trying to keep the engine running by pressing the gas? If so then I'm 100% sure it is a bad fuel pressure regulator. Good luck finding out what it is.