Is there any spark at all? Why did you replace the coil? They sell cheap spark plug testers at autozone.
Also you must find out what the check engine light code is. This will get you to the answer quicker. Autozone will scan your truck for free. Stop changing things unless you test them and determine that they are bad. Autozone or a place like that will test many things like coils, ignition modules and almost any sensor for free.
What kind of spark plugs did you put in? Bosch are junk even new ones, I suggest A/C Delco.
I also see that your battery was low and your alternator was bad. Your truck has a security feature from the factory called PASSLOCK. This system works in conjunction with a resistor either in your ignition switch or in a passlock module. This resistor has a specific value that is unique to your truck. Sometimes when the battery is low this resistror fails. The passlock system will not allow fuel into the motor if it is set off or broken. Unfortunatly a chevy dealer is almost always the only shop in town that has the capability to determine if this system is failing.
The neutral switch may be the cause also, but test it before you replace it. Stop changing things just because you assume that they may be the problem. Test them first. Jump out the fuel pump and test the fuel pressure. If you don't know how, there is a fuel pump relay in the- under the hood- relay center. Take it out and look at the wiring diagram. There are two terminals marked 85 and 86. Jump them out with a small wire. This will jump out the fuel pump directly. It should run and you then could test the fuel pressure. Do not worry about how long the pump runs because the fuel is just recirculating back to the tank. Keep me posted
Monday, December 3rd, 2007 AT 2:36 PM