can anyone give me suggestions on what to check for no spark? I checked ground on the drivers head. I have new plugs and wires. Im stumped.

 

Are the coils firing? If not you need to check all connections at the coil harnesses. Check to see if your getting injector pulse as well. What method are you using to check spark? If your not getting spark or injector pulse, id be leaning towards crank sensor or pcm. need to run a few checks to see.

 

^ what he said. So theres no spark on any cylinders? Can you get a scan tool or o-scope on it?

 

I had the same problem one day - Swap your fan relay with your ignition relay and see if that fixes the issue. Sometimes they just fail randomly.

 

I checked the crank and cam sensors, both good. The wiring harness to the coils are both good. To check for spark, I pulled a plug out of the head and plugged it back into the wire and had my wife start the car. No spark. I will try to swap fuzes after work today.

 

A spark plug will not fire just plugged into the end of a wire. The plug has to be grounded to something. The plug becomes grounded when it is screwed into the head. Either use a spark plug tester or ground out the plug and try again. Or use a screw driver. Place the end of the screw driver into the wire and let the spark jump from the screw driver to a ground. start off a 1/2 inch away.

 

ok. got it. I tried it and still nothing. I gotta have a loose ground going somewere. Im gonna stop by the local chevy dealership and ask for the schematics so I can pin test this thing to death.

I used a can of seafoam not too long ago and poured the entire can into a half a tank of gas. I have heard that sometimes the seafoam gasses and **** can coat your plugs and make em not work?????????

 

I've heard that too BUT you already proved that you don't have spark at the wires with the screwdriver trick so it doesn't matter if plugs are fouled or not.All eight wires have no spark? No DTC codes, no security light?

 

Got It. I took your advice and switched the #2 Fan fuze with the IGN fuse and it fired right up. I seems to be running fine now. About to take her out ....
Thanks for the help.

 

Great news! Good call LS1Formulation!

 

Good job man. Glad to hear shes running again. Yea you would of pin tested the harness and found no current. Good rule of thumb.....always check your fuses and relays first.