This is in regards to my L98 engine.

There are several different scenarios which can cause this problem. An example would be if I were on the highway and I punched the accelerator to cause a 4-2 downshift. The engine will be pulling ~3,500 or so and climbing, and as it's accelerating, the engine just cuts completely out. It'll be pulling hard, and then the next second, the tach drops down to idle or below idle, almost as if I had just turned the key off. It will stay like this as I'm coasting and when I let off of the pedal a bit, all of the sudden the engine will just instantaneously "turn back on" and pick up right where it left off, as if nothing happened. When this is happening, the car fairly violent accelerates/decelerates depending on what the engine is doing (not surprisingly).

What makes this particularly odd is the instantaneous nature with which this happens: it completely cuts out without any warning at all, and it turns right back on just as instantaneously as it cut out. There's no sputtering or anything and the engine pulls hard before and after it's cut out. Moreover, this doesn't always happen at the same engine speed--I've noticed it usually happens on the highway. All of the lights in the car remain on, so I know the electricity is not completely cutting out.

What does this sound like to you? Fuel? Electric?

Thanks for any help!

 

Sounds like the ECM is shutting you down.

What is your oil pressure like? maybe its dropping too much...

 

Oil pressure is definitely fine (for some reason, that's always the first thing I check).

 

whens the last time you did a tune up? also, disconnect the negative battery cable for a couple minutes

 

A friend's 91 Camaro V6 was doing the same thing and it turned out to be a +12V somewhere near the front of the car. I never found it, really, but he called me one day because the car wouldn't start. I put a meter on the battery and started shaking wires. I grabbed a split loom wire assembly running along the top of the radiator and shook it really hard. The battery voltage started sweeping all over the place. After shaking it a few times, the car started and he hasn't had the problem since.