I think this is a tune related issue. I recently did some maintenance on my car, changed the oil jet bolts, added an alloy craft oil pan baffle, new headgasket, and toda valve springs. I double and triple checked to make sure that everything is back together, the wires are plugged in and the ground on the back of my head is tight. My car worked fine on the tune prior to doing all of this. I started my car up today and drove it down the street, after doing a WOT run, I was slowing my car down and my car shut off without warning, like if the battery died. I started it back up and it worked fine again until I came into my neighborhood and coasted a turn, it shut off on me again. I can now replicate this problem by going at a decent speed and stopping. The car will undoubtedly turn off. To make matters worst, sometimes when starting the car up again, it will cut off on me. For example if I started my car up again, put it in first to move 5 feet then go back to neutral, it will cut off.

 

So it's like you turning the key of or is it just the engine stalling?
The dash lights shutoff?

 

Sounds like the engine is over shooting the IACV and ether stalling for a second or shutting off.

 

The engine is stalling, because the RPMS drop drastically and it just cuts out. It's very quick and sudden, it's like someone just turned off the car.

 

Does it still shut off if you hold the rpms?

 

Yes it does, even if I try to kept my foot on the throttle to save it, it's like someone ripped out the battery. Although it isn't my battery, because my kpro is still datalogging when my car shuts off and my radio still works.

 

I'm starting to think this isn't a Tune related problem. It's something electrical for sure, I don't know what would cause a car to suddenly lose power. Everything worked perfectly prior to the headgasket install. The ground on the head seems like it is on very tight. My car only has 80k miles on it.

 

that's exactly what i'm thinking. in the k-manager software there's a slider that you can play with for the iacv. i'd try messing with that.

 

I disabled the IACV. I'm going to delete this thread and move this to under the hood. I don't think it is the tune.