C4 Corvette won’t start? Not sure what is causing this issue? Here is a list of common and top reasons your Corvette won’t start. This post will list reasons it happens. Once this post is completed a process of how to diagnose and fix your starting problems.
Just a few things to consider. Sometimes your issue might be caused by more than one issue. Also, try to track down the issue before spending unneeded money on new parts before you know for sure what is wrong. There is nothing more frustrating than purchasing a new part, removing the old part, installing the new part, only to find it doesn’t fix the issue you’re working on.
Check the easy things first
- Check your battery – is it charged enough to start the engine? Need to replace it?
- Make sure you have gas – Yes, I know duh. But I’ve seen people have issues when their gas tank is low. This can indicate a problem with your fuel pump. Also, gas gages are a common problem area and could be showing you an incorrect reading.
- Check your transmission – If your Corvette is an automatic make sure its in park or neutral will work too. If you have a manual make sure your Corvette is in reverse and you press down the clutch pedal when trying to start. A lot of people don’t know a manual transmission should be in reverse when turning off or starting your Corvette. After all these years the lock out parts installed way back in the 80s-90s could be worn out and cause these type items to cause issues.
- Check your error codes – This can usually help you track down where to at least start looking at your issues. Not sure how to get your codes? See how here
Are your plugs getting spark?
Pull a plug from the engine and check for a spark when turning it over. Not getting spark? There might be issues with your spark plugs. If they haven’t been changed in a long time you might want to replace them. Are your spark plug wires in good working order? This is another easy relatively cheap item to change.
If the above items are good you probably have a distributor cap issue. How old is your distributor? Is it time to replace the components to help your Corvette run better. If their is some burn marks on your cap it could indicate the charge is jumping somewhere it should’nt go.
Do you have fuel pressure?
Listen for the fuel pump to start when you first turn the car on before starting the engine for the first couple of seconds. That will tell you if the fuel pump is operating but it could still be a fuel problem. The problem might be the filter, regulator, or even the fuel pump itself. You will need to check the fuel pressure, you can either buy or rent a fuel gage or by push in the valve to see if fuel squirts out.
How to check fuel pressure. Take a fuel pressure gage and attach it to the schraeder valve, it looks like a tire valve. Turn the key to the on position. If you are having starting trouble the pressure will probably drop right after it gets to 38 or 40 PSI. When the pump turns off it will probably leak back to zero within a few minutes. After you prime the system, pinch off the return line near the tank, if the pressure drop stops it is a bad fuel pressure regulator.
Next pinch off the feed line, if the pressure holds then the leak is before the point where you pinched the line possibly the fuel pump check valve or a hole in the metal line on the sending unit caused by rubbing on the inside of the tank. If so, you should visibly be able to see this if you pull the pump and the sending unit or the pulse dampener which is the piece between the pump and metal line on the sending unit.
Replaced anything recently?
Sometimes the last item replaced or repaired didn’t get done correctly. When I replaced my intake gaskets and repaired my leaks at the china wall, I installed my distributor incorrectly causing the spark plugs to get the spark at the incorrect time. If you pull out your gears that turn the distributor you must make sure you get the gear teeth back in the exact same place unless you want some time issues.
Also, just because you bought a new part doesn’t guarantee its a good part. I’ve bought new parts in the past that turned out to be bad.
Conclusion
Truthfully their area a lot of things that cause your C4 Corvette to not start. These are just a few of the common items that usually cause the issues. Still, one of the best things you can have is a shop manual about your particular year Corvette. Take a look here if you are thinking about getting one. The actual GM shop manual is the best thing you can buy to track down your particular problem.
Questions or concerns with this post, leave me a comment and I’ll be sure to get back to you.
