2001 Bullitt with ‘03 Cobra swap Electrical Issue Help Please

Thank you in advance for reading. I have a 2001 Bullitt with a 2003 Cobra motor swap. I’m chasing a very annoying issue which seems to be electrical. The car will idle perfectly, in neutral I can rev to redline with zero issues. In gear, I can ease in to it and climb steadily to redline with no issue.

The issue happens when I’m in gear, and try to go wide open throttle. The car acts like I turned the key off, but doesn’t stall. I just lose all power momentarily, take my foot off gas pedal and it comes back to life. The only thing I did since the last time it ran fine was charge the AC. After charging AC, the AC blows ice cold, but the next time I drove it...this issue started. I’m certain it’s coincidental, but just mentioning in case I’m missing something.

I’ve done a bunch of searching on the forums and have tried the following already:
-new OEM coil packs (no change)
-new crank position sensor (no change)
-unplugged alternator just to satisfy curiosity and make sure it wasn’t doing something strange(no change)
-TPS check out fine
-IAC checks out fine
-Mass air sensor cleaned
-new fuel filter
-had battery load tested and it checked out
-checked grounds and all seem fine
-had car data logged on the dyno, fuel system is perfect

Anyone have any other suggestions on chasing down this gremlin.

So after throwing some parts at it, I finally did what I always forget to do, and start simple. The positive battery cable from the trunk mounted battery was leaning on the header. Found it, repaired, and now running great again.

Ah, there’s the rub! Wish we could see the rest of the car. Sounds like a great combination. If it’s anything close to the Terminated Bullitt build, you’ve got yourself a heck of a build.

Nice catch, and glad to see you worked it out.

MikeD1776 said:

So after throwing some parts at it, I finally did what I always forget to do, and start simple. The positive battery cable from the trunk mounted battery was leaning on the header. Found it, repaired, and now running great again.

View attachment 1663321 View attachment 1663321

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Damn that could have been VERY bad.

streetpilot said:

Ah, there’s the rub! Wish we could see the rest of the car. Sounds like a great combination. If it’s anything close to the Terminated Bullitt build, you’ve got yourself a heck of a build.

Nice catch, and glad to see you worked it out.

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thanks man. It was driving me nuts.

She makes 467rwhp...for now. I’m sure I’ll fall fast down the slippery slope...return style fuel system, whipple...it would almost be a shame to not keep going now hahah.

Black02GT said:

Damn that could have been VERY bad.

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No doubt. Felt very lucky to find it.

Not to jump on your back but yeah it could have been bad. Same thing happened to me but with my fan wiring, sitting on freeway noticed smoke from fender, pulled over immediately and found wire shorting out on my header that I forgot to zip tie to the fender and actually started to burn the carpet just inside the firewall.

Be careful out there, never hurts to check your wiring once and a while

RBCA s197 said:

Not to jump on your back but yeah it could have been bad. Same thing happened to me but with my fan wiring, sitting on freeway noticed smoke from fender, pulled over immediately and found wire shorting out on my header that I forgot to zip tie to the fender and actually started to burn the carpet just inside the firewall.

Be careful out there, never hurts to check your wiring once and a while

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Lesson learned for sure. Glad you found your issue in time as well.

I'm surprised it didn't short and cause a fire. Please make sure you have a fuse on that wire heading back to the trunk.

I like to keep an h3r halon extinguisher around. Hope like hell I never have to use it .