Random cut-off problem

[cradicg]

I have a gremlin I need help with. On three occasions over the last month, my car has stopped running on the highway. It didn't sputter and then die; I just suddenly notice the car is no longer running. This happens when I am approaching off ramps from the highway. The battery and check engine lights are all that come on, and there are no codes in the computer (I checked with my SCT). I have tried repeating various conditions (high rpm, high speed, sudden deceleration) but can not intentionally cause the problem. The only additional clue I may have was last night. I was approaching a stop light in town, and my idle dipped low (below 500 rpm) and the lights dimmed, but then it came back up. Could my idle be dropping too low to stay running on the highway? Like I said, I don't realize the car is no longer running until I try to slow down and turn off the highway (no power steering or brakes). The car immediately starts back up when I turn the car key. The vast majority of my car is brand new. Here is my current setup (all newer parts are less than 2 months old, if part is not listed, it's 1999 stock)....

1999 Cobra coupe
Ford Racing 4.6l DOHC crate motor (03/04 Mach 1 engine)
JLT CAI
SCT Xcal2
BBK long tubes
BBK catted X-pipe
Magnaflow cat-backs
Tremec TKO600
SPEC aluminum flywheel & Centerforce clutch
Ford Racing aluminum driveshaft

Here is my last dyno sheet, red is after all the mods....

<a href="http://photobucket.com/" target="_blank"><img src="http://i116.photobucket.com/albums/o6/cursed99cobra/8233.jpg" border="0" alt="Photobucket - Video and Image Hosting"></a>

Thanks in advance for any help!

 

[JLTucker]

At any speed above 55 this will happen. Your cramming air into the intake filter and closing the throttle blade. Now the air is bouncing back and forth across the MAF sensor and it doesn't know what to do.
Best suggestion is to down shift. This is better for your brakes as well.

Thanks
Jay

 

[SVT98Snake]

Hey Jay....what mods in your 03 got you to 517 aside from the JLT? Love mine BTW.

 

[Uncle Meat]

Hey Jay....what mods in your 03 got you to 517 aside from the JLT? Love mine BTW.

C'mon! Everybody knows that a full JLT CAI setup is guaranteed to give you at least 120RWHP! I hear the RAI is good for 100!

Just kidding Jay!

U.M.

 

[SVT98Snake]

C'mon! Everybody knows that a full JLT CAI setup is guaranteed to give you at least 120RWHP! I hear the RAI is good for 100!

Just kidding Jay!

U.M.

I'll tell you what.....just the sticker is worth 50.

j/k

I did gain about 20 over a KN cone with Jay's kit. He even used my testimony on his site....so there.

Great guy and service too.

 

[cradicg]

Thanks JLT

At any speed above 55 this will happen. Your cramming air into the intake filter and closing the throttle blade. Now the air is bouncing back and forth across the MAF sensor and it doesn't know what to do.
Best suggestion is to down shift. This is better for your brakes as well.

Thanks
Jay

So is this associated with aftermarket intakes? I can't see the general public being OK with thier Mustangs cutting off once in while. I'll try the down shifting and see if that helps.

On a side note, thanks for quoting me the individual replacement parts for my CAI. I will contact you after the holiday season to get what I need. At a minimum I need to replace the broken nipple. I will try to trim the split on the elbows since they are minor.

George