Last night my car developed an issue down track. 2nd round of elims, it backfired twice through the exhaust, but I still got the win. Checked all rocker arms between rounds and they all looked good. Decided to run it 3rd round and if anything felt wrong, I'd abort the run. This time, it cut off for a split second like someone turned the key off and back on, got the win again. 4th round, it did the same thing twice so I aborted the run and took the loss. It seems like an ignition issue but I don't want to throw parts at it hoping to fix it. My setup is simple. MSD 6al2 (new this past winter) with an hvc coil. Any help is appreciated.

I would ckeck the plugs and plug wires first.

Master shutoff.

If the car sit outside through rain then water tends to get inside and cause corrosion. Been there done that.

Try a different ignition switch.

I posted this in a different thread a few days ago.

quote:

Mine wasn't as bad, just a random miss that slowed the car down .03. It wasn't a big deal, if it skipped I either didn't need to kill .03 or I would spray a little (depends on how I was dialed). I had (over)100% spares so I changed EVERYTHING, 1 part at a time, including the engine. Finally one day my car wouldn't start. I found no voltage from the ignition switch. I ran a wire from the water pump switch to the ign box. Car started and miss was gone. This was with a 7AL2, ~20 years ago.

Thanks Clint. The car sits in a trailer, never gets wet but I did consider the master cutoff. I'll take a look at the plug wires today, I don't like how they are run,they could be chafed. I know in my post I mentioned it felt like that key was turned off and back on but this car doesn't have a key, it goes through an ARC8000 panel but I'll inspect the ignition wire from the panel. I also have a spare 6al somewhere, if all else fails, I'll put that on and see what happens. Thanks for the advice.

Had a issue years ago, and it was the battery. Battery was low on water, and I swapped it out after the I got lucky, in that round. It was 30 years ago before AGM, or lithium batteries

Could the 6AL box be getting too warm? Is it mounted in the engine compartment?

I've had a somewhat similar issue with my 6AL, and plan to move it to the driver's compartment.

But mine quit once in the staging lanes, but I was able to restart the truck right away. Since then I put an emergency by-pass around the key switch.

quote:

Originally posted by threepedals:
Had a issue years ago, and it was the battery. Battery was low on water, and I swapped it out after the I got lucky, in that round. It was 30 years ago before AGM, or lithium batteries

I run a 16V XS battery, about a year old. I do have a spare I can try if it comes to that.

quote:

Originally posted by Bad Nusz:
Could the 6AL box be getting too warm? Is it mounted in the engine compartment?

I've had a somewhat similar issue with my 6AL, and plan to move it to the driver's compartment.

But mine quit once in the staging lanes, but I was able to restart the truck right away. Since then I put an emergency by-pass around the key switch.

My box is in the passenger compartment for that reason.

Sounds like a weak ground or master switch. Do you ground box to battery?

I have two separate grounds from my battery for that reason, and two grounds to the ignition from different sources.

quote:

Originally posted by Don Higgins Crew Chief Pro Software:
Sounds like a weak ground or master switch. Do you ground box to battery?

I have two separate grounds from my battery for that reason, and two grounds to the ignition from different sources.

I think you're right. While checking lash today, my neighbor noticed a nut missing off of a bulkhead connection for a ground distribution block in the engine compartment. The coil ground is connected to that distribution block. The wire connected to bulkhead fitting would spark when I bumped the motor over. I'll get a new nut and do some testing this week.

I have 3 years on a 6AL2 without any problems so far. Mounted it inside away from the heat.

Im with Don on this one. Sounds like a grounding issue. Check them all.

I had a similar issue one time and it turned out to be a loose wire on ignition switch. I also had a 7AL-2 box go bad that did a lot of popping and banging. I have tore up some stuff. Lol.

What Curly said

RB72, you have a HVC coil -NOT- a HVCII coil right??? HVCII coil's are known to have shorting issues....Tech West found mine.