Cliff notes: Just rebuilt motor, got it back together, randomly cuts out. Like electrically. Only does it on acceleration, hard braking, or if i hit a big bump. I have checked the grounds several times, cleaned all of them, tried another new battery, etc. Any suggestions appreciated. I dont expect anyone to read all the rambling lol

I just had the motor out of the car after spinning a bearing. The motor is back in and perfectly sounds i now have over 800 miles on it. Took it by the tuner to check everything out. Sitting still in his driveway everything was perfect, checked all sensors, crankshaft pos relearn, balance test came back perfect, evertying is great. When i am driving the car, thats when the issues arise. If i hit a large bump it feels like the car just completely dies, then restarts. It will run like ****, and won't keep an idle. If i turn the key off, then restart everything is fine for a while. I tried to powershift 3rd gear on the highway today on the way to work, and it completely cut-out. It came back on about a second later and i continued to drive.
The 2 grounds on the back of the head were loose, but i tighten them, and still have the same issues.
Also, i have the whine in the stereo at times. My speedometer acts normal under normal driving, but if i got wide open, it;s all over the place, it jumps at least 20-40 mph wide open, as soon as i let out, it goes back to normal.
I'm so tired of cars.
Tomorrow i am going to re-check and clean all the grounds, does anyone else have any suggestion as to what the hell could cause all of this ****?

Any suggestions are appreciated

I've also noticed the speedometer jumps when i rev it sometimes. Seems worse with the ac on.

wow, i completely cleaned the battery terminals, check the grounds, there is a good connection at the alternator(although i didn't remove it to check the connector). And it still does it. Doesn't as bad, but i only went 10 miles. Speedometer jumps all over the place wide open throttle, when i hit some gears most of the lights come on and the service vehicle one stays on until i turn it off. I'm seriously so pissed off with this damn car, i wish someone would steal the damn thing.

I know I'm not the first person to have a problem like this...

Tried another battery today from another car, battery is only 2 months old and it still does the same bullshit.

I just drove it a minute ago at luch. Went through a drive thru, everything was fine. Pull up to a red light, sit for a minute, i get about 10 foot and it lost all power, pushed in the clutch it was barley running, dumped the clutch at 4krpm to avoid the guy behind me from hitting me, go to hit 2nd, lost all power again.

Any suggetions appreciated.

 

did you check the pcm connectors

 

So you are not getting SES codes just BCM codes?

 

no i was scanning one day and noticed it cuting in and out
the every now and again i would have my knee into it and it would just turn off
out of the blue speraticly

 

Have you secured your battery down to the tray? I had a similar problem and it was my battery grounding out against the fender well at WOT. Hope it's something simple

 

HAHAHA This happened to me at the track! But I broke mine from pulling the wheels

 

I have checked PCM Connections multiple times, checked all engine bay grounds, battery is securely mounted, battery terminals are tight, NO CODES

Could is possible be a bad PCM somehow?
Someone told me it could be the alternator, but wouldn't the battery keep it running?

I guess I'm going to throw a fuel pressure gauge on it and observe... Also, i have siwtched in a different fuel pump relay just in case it was a intermittently bad relay. Oh well.

 

it sounds like a short of some sort good luck!