I've got a 2002 z28 manual with 100+ miles on it. Recently it has trouble starting, but not all the time. It will crank and it sounds normal, but it just will not fire up. Let it rest for a bit and it will fire up fine. Probably the best way to describe it is that it takes awhile to start up. However, sometimes it will start on the first try. There doesn't appear to be any pattern. Any idea on how I can trouble shoot this issue?

Thanks in advance!

 

Have you tuned it up lately? Checked basic things like the air filter, plugs and wires? Could also be fuel pump related. Try turning the key to ON without starting, can you hear the pump come on? If it starts right away after having the key on for a few seconds before starting (allowing the pump time to build pressure) it could be a fuel pressure issue.

 

Thanks for the quick reply. Air filter is brand new. Plugs and wires look good, but the wires are original... might not hurt to replace them. Probably wouldn't hurt to change out the fuel filter as well... What's the easiest way to determine if the fuel pump is gong bad is the above (turn on to let pressure build) a good enough proxy? Only concern there is that it's not always a problem so will be hard to know if that really is doing the trick. Will give it a try though... Thanks!

 

It could be starting to fail on you. Best way would be measue the fuel pressure on the fuel rail on the engine. Not sure what it is supposed to be though. I'm sure someone will chime in. I was justa bsaying the next time it cranks but wont start, just let the key off for a few seconds to see if the pump needs a bit of time to build pressure.

 

You need to do a fuel pressure test.

 

I had this exact problem and it ended up being the crankshaft position sensor. I would check that before you try anything radical.

 

stop by the local parts store and have them scann the cars computer sytem for trouble codes, if you find any write them down and let us know what they are. try cylcling (turn key on and off waiting each time for pump to stop before turning off) the key a few times before starting. if the fuel pump or fuel pressure regulator is failing or getting weak it wont punp up to proper pressure on only one cycle.

 

I had this same issue as well. I ended up changing the plugs and wires and the trouble still persisted. At this point I decided to change the fuel filter due to it not being changed in about 3 years. I am still having the issue so I am going to go to a parts store to have it scanned and see if they can figure it out before renting or buying the tool needed to check the fuel pressure. I am almost certain it isn't the fuel pump on mine due to the fact that mine has been acting up for almost a month and a half now, but then again you never know. I would say the best bet for you and myself as well would be to do as suggested above and get your car scanned to see what if any error codes come up.

 

As an afterthought you might want to check under the hood where your fuses and relays are. I just checked mine and they both looked good but I went ahead and replaced them. Now my Camaro starts up and runs just like a champ. Might be something for you to check and if it works it is a cheap and easy fix.

 

Your car needs four basic things to start. Air, Fuel, Compression and spark. It is very unlikely that you are starving the engine of air and compression issues are not intermittent. That leaves Spark or Fuel. You need to check the car for Spark and fuel at the time it will not start. Spark testers are cheap and at most parts stores. Your going to want to do a fuel pressure test. If you have spark and fuel pressure next your going to get a fuel injector noid light to verify the injectors are firing.

Just a FYI one of the most common causes of this condition is fuel plump failing. Also Spark plug wires are good for about 7 years. After that they start to build up resistance and can cause the coil to fail or damage other parts of your ignition you should get them replaced. I do not think your current issue is being caused by your wires. These issues normally show up hot or under load.