Any ideas why my truck eats coils?

[rocky]

Some of you will remember WR two years ago in that deep freeze when my truck was one of the ones that refused to start in the cold. After a while.....it burst into life.
That no start then start routine continued. The symptoms are the same, starter turns, perhaps you get a single pop or a couple of cylinders firing then nothing. Replacing the coil fixed the problem.

Its not the first coil I've had go bad and apparently not the last.

This time, it was the first sub zero cold snap that did it in. I left it to sulk the first time, then dropped a trickle charge in to it. Friday, by luck, I left the ignition on for a few minutes after an unsuccessful start while I got tools and a new coil. Coming back, I tried it again, started right up. Today, using the same almost glow plug like pause before starting approach and it starts.

Wasn't able to drop a replacement in today (Soccer Tournament to referee). But the question remains. Why are the coils lasting just a few thousand miles. Used to get tens of thousands of miles out of them.

 

[donb]

Double check the ground.

My 3.9 NAS did the same. Or they would get crazy hot. When I sold it I had the local garage check the grounds and I think they ran a new ground wire. The new owner hasn't complained about it and he is local.

 

[rovercolorado]

As above it's the GROUND.
Check everything going to ground all the big stuff and small.
I also found water in my ECU and cleaning that out helped as well.

 

[rocky]

Ground... Better ground for the coil... that ones easy to test as well.

 

[Red90]

The coil does not have a ground. The low voltage side grounds through the ignition module and the high voltage side through the spark plugs. You want to look at the engine grounds.

 

[rocky]

The coil does not have a ground. The low voltage side grounds through the ignition module and the high voltage side through the spark plugs. You want to look at the engine grounds.

Think you are on to something. Whenever it refuses to start, the starter motor sounds weak lacking in vigor. As if the battery is drained. But its not. If the ground to the engine is compromised then any ice water etc is just going to make it worse.

How many grounds does the engine need? Where do they go from/to. Is there a particular wire gage to use for grounds? I'm so not looking forward to crawling under my truck on the cold ground......