jclayc

iTrader: (8)

Hi everyone,

I had the LS6 in my 2005 CTS-V rebuilt and I reinstalled it this weekend. It started right up and had good oil pressure. I shut it down after about 60 seconds so I could look around. Fine. I re-started it and it ran for another 60 seconds before all electrical died and the engine stopped. I've got nothing, not even dome lights.

I can't find any blown fuses. The + and - leads coming off the battery and the battery were pretty hot to the touch. Not good. When both leads are connected and I run a voltmeter across the posts, I get 0.08v. When the - is disconnected, I get around 11.8v from the battery (it's been sitting for about 6 weeks).

When I try to connect the - lead to the battery, it sparks, big time - even when the alternator lead and plug are disconnected.

I've checked and don't see the + wires to the starter or alternator touching the headers. I have the big four ground wires connected to the back of the heads. Any thoughts on causes?

Thanks

LS1-450

iTrader: (33)

There's a ground connected to a positive lead somewhere. Must be the case if the - sparks when connecting to battery. If I had to take a wild guess, would say maybe @ the starter solenoid or a nicked wire insulator somewhere.

ls1 1990 VN

As above,
The starter solenoid + & - terminals could well be touching each other.
Any other wires connected to your battery terminals that could be crossed.

jclayc

iTrader: (8)

Thanks for the replies. I think I'm going to have to take this to someone. Any suggestions in North NJ? I'll call my engine builder (LRB up in Franklin NJ) tomorrow and ask them...

I replaced the starter with a new MSD one, replaced the main + wire that goes from the battery to the fusebox, starter and the alternator (just in case there was some damage to it) and rewired the one wire going to the starter soleniod b/c some insulation was missing from it. Everything started back up but the same thing happened again after about 5 minutes running.

When I disconnect the + to the alternator and try to reconnect the - lead, it still sparks badly. But when I have the alternator + connected and disconnect the starter + lead and reconnect the - lead to the battery, the sparking goes away and I get little things like my interior lights back. Am I right that this says the issue must be in the starter wiring?

Back to the suggestions above:
You could mean, literally, one of the four engine grounds is connected to a + source. They're not. It's more likely that a + lead is grounding - that's the same thing, right?

They're very close to one another by the design of the factory and MSD starters but they're not touching...

The + connects to just 3 places (main fuse box, starter and alternator) & those are right. The - connects to 3 places (the body, the passenger's side head and into the main ground system). I guess it could be that one of the grounds downstream is mis-connected??

This is probably frustrating to read/try to help with...

stoning_volcom

iTrader: (6)

If you can put the engine back in, you can figure out what went wrong. Just make a list of what you changed. Imnot talking performance wise, just like you stated you replaced some wireing and what not. Just run back through and think of what had to come off to get the engine out, and back in. If the car started then died,.... i wouldnt think it would be a direct missmatch of pos to neg. if that was the case then that would have been alot worse than it just shutting off, have you tried to install the stock starter?

LS1-450

iTrader: (33)

Yes, it's the same thing. Doesn't have to be one of the engine grounds. It is a ground or a device incorrectly wired or a short. Somewhere, you will find a - that should be a + or a plus that should be a minus; same thing. If there is spark when connecting to the battery ground terminal, something in the ground circuit it connected to +. The four on the engine are only part of the ground circuit that eventually terminates to the battery. Remember that the car chassis is also grounded to the battery. Anything that uses the chassis as a ground point can be the culprit, as well.

jclayc

iTrader: (8)

Status update: I did notice, on the new MSD starter, there was a little burn on the solenoid, so I may have inadvertently had the + pushed too far toward the engine and solenoid, causing the problem the 2nd time. I adjusted the + lead and wrapped more heat tape around everything. I also shimmed the starter to decrease both the pinion depth and the tooth engagement, thinking maybe the pinion was getting stuck and leaving the starter "on". Finally, and I don't know if this is related, but I figured out that I had my drive belt routed incorrectly, so I fixed that (see the image below - red is how I had it routed).

After running it up to operating temp at ~1000 RPM, cooling it off, then running it at ~2000-2500 RPM up to operating temp, I still have power and no obvious problems. The - lead to the battery is hot but not melty-hot so I'm not sure that's from more than just being under the hood when the engine is up to temp.