i would like this to be a sticky eventualy.
Before asking what is wrong with your vehicle and why it doesnt run look here first.

1) is it getting fuel?: if your engine wont fire on your chevy, the fuel pump is the place to check, all it takes is your ears in a fuel injection car, click the ignition on and listen for a whine or a buzz if none, it is time to drop the tank and test for power first and replace pump if power at the tank and no buzz, if no power it will be a ground or relay or fuse, if only high rpm hessitaion replace fuel filter, if still hesitation keep going

2)does it have spark?: pull a spark plug, touch the ground tab (the little thing coming off the end of the plug) to the engine (on metal) and have a friend turn the vehicle over (but prop it and look, don't hold the plug unless u like shocking results), if no spark check the condition of wires (replace if cracked,burnt or frayed) if your truck has carburation and no spark, the module is the first thing to replace followed by the coil (they are found inside the distributor on HEI units and at the other end of the middle wires on 88-98 pickups and one for each cylinder for 98 and up chev pickups), ) and try an electrical tune-up (cap, rotor, plugs and wires) when replacing wires or plugs ALWAYS use dielectric grease, if you dont the first time u go through water of any sort, you could have a bad running truck on your hands (plus the corrosion factor)

3) if u have fuel and spark and it has been a long time since the last tune-up do one, this includes fuel filter (replace every 6 mos-1 yr) dist. cap and rotor, plugs, wires, air filter and check the pcv valve to see if it has vaccum, if not replace it or it could cause blow-by on your rings (go-to place if you have a fouled or oil on the inside of your plug).

4) on fuel injection engines there are many sensors and gizmos that make your engine run the to the best of knowledge at the time, O2 sensors are recomended to be changed every 100k, these are often the cause of the check-engine light, throttle positioning sensors go too, as well as MAF (Mass Airflow Sensors) and for these, preventitive maintenence of them can be done by sraying with intake cleaner while running or removed, it is always wise to look for codes or to take it to a trusted local mechanic to diagnose it, dealerships seem to always charge an arm and a leg for not even doing anything

5) if you got this far, the problem may be a little more serious, do a compression test on all cyl, it should be at least 150 psi for good engines and all cylinders should be within 20lbs of the others if u have a dead cyl see a mechanic, major engine damage could have occured

IF YOUR VEHICLE EVER OVERHEATS PULL OVER IEMEDIATELY OR MAJOR DAMAGE WILL HAPPEN!
6) if your vehicle is overheating, change the thermostat, it should be changed every year or 2 anyway, if still overheating check the rad for crap in it (bugs,dust, newspaper and things like that) next if still overheating .still getting hot? replace the rad cap, i have seen people replace their whole cooling system and spend $$$$ just because of a failed rad cap.make sure the fan is working properly if electric make sure it turns on and if engine driven clutch fan spin the fan if not much resistance, the replace clutch part of fan if lost of resistance. next check the coolant, did you mix GM's dex-cool with regular stuff? if yes then drain all the coolant flush the system a couple times, check the rad for blocked passages from corrosion or gunk through the rad cap (if yours is on the rad) and replace coolant, also do the same if your coolant smells sickeningly sweet, this means your coolant has passed its useful life span

I hope this helps most people here this is for general problems found in most chevy's i am not a mechanic, but i have been working on my, my familys' and friends chevys for 14 years, i changed out the heads on a small block chevy at 12 years old, and had my first performance 350 built at 20 years old (without any help either) if none of these apply to you or if you need help with different matters, then by all means post your problem. if this helps, then awesome and im glad i could help. if you have something to add then by all means add it, i am no means an expert but i have a lot of knowledge on chevys. this thread is to help de-clutter the boards a bit as many problems are fixed by doing these steps

**edited for added content and spacing of paragraphs for easier reading**

 

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