No Spark

TREY SCOTT

MEMBER
2006 GMC SIERRA
4.8L
V8
4WD
AUTOMATIC
293,000 MILES

It all started with my starter going out, it fully went out. So, I changed it and turned over the truck and normally it would start but wouldn’t. So, I checked if my plugs were filled, and they weren’t (didn’t except them to be just changed wires and plugs). So, I changed the crank sensor and cam sensor and still not getting spark. What could it be?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

I have a feeling that while working on the truck, the ground fell apart for the coil packs. It's not an uncommon issue.

All of the coils share a common ground. It is on the driver's side of the engine closer to the front of the block and about two thirds of the way down. The connector there commonly falls apart.

If you lost spark to all plugs, this is my first suspect. Simply do this.

1) Key off.
2) Disconnect one coil pack connector.
3) Locate the black wire in the wiring harness and check for continuity to ground.

If there is no continuity, locate the black ground that ties in with the coil wiring harness at the top of the engine. Follow it down to the side of the engine I mentioned and check it. Note: It may look good but move it around. Many times, when moved, they fall apart.

Let me know what you find. Also, here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Take care

Joe

See pic below. Highlighted how they all tie together.

Image (Click to make bigger)