3 broken ground wires
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 23,242
Likes: 117
From: San Antonio Texas
3 broken ground wires
I suspected I'd had a bad ground, so I got under the car for a check. I found a stud that holds the cat bracket on the driver side that had a ground strap and three other wires attached to the stud with a nut. When I turned the nut, the whole stud turned revealing the wires were broken to a couple and were barely attached to another. I think gravity was holding them in place. Anybody know what these three grounds are to? Now I've got to figure out how to extend them and reattach them into that black hole!
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 23,242
Likes: 117
From: San Antonio Texas
Well, I spent the day under that miserable POS in the Texas sun and got all the grounds repaired. Took it down the road a couple of miles to let it warm up. Got a block from the house and it did it's shut off trick again. It only lasts about 3 or 4 seconds and it only does it once a day as it comes up to temp. but it does it EVERY time. I'd light it and dance by the glow of it but the wife took the lighter away and I'm too damn tired to rub sticks together.
Instructor
Joined: May 2010
Posts: 235
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From: Southern Colorado
Does it completely shut off?
How long into the warmup does it happen? Is it pretty consistent? Does it change when the outside temp changes significantly?
If the car completely cools down during the day, will it happen again?
If you let it warm up without going down the raod, will it happen?
Does it happen as you let off the gas, or will it even happen under acceleration?
Sorry if you've answered these before.
How long into the warmup does it happen? Is it pretty consistent? Does it change when the outside temp changes significantly?
If the car completely cools down during the day, will it happen again?
If you let it warm up without going down the raod, will it happen?
Does it happen as you let off the gas, or will it even happen under acceleration?
Sorry if you've answered these before.
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 23,242
Likes: 117
From: San Antonio Texas
It does it on EVERY warm up cycle when it gets between 200*-210*. I let it idle with a penny in the linkage (2200rpm) yesterday till it got to 230* and it didn't glitch till I reved it up to about 3000rpm. It usually does it on light acceleration as it comes through the temp band and hits anywhere between 200* to 210*. After it has it's little seizure, it is OK the rest of the drive till you stop and let it cool below 180*. I suspect the low rez signal from the MSD Opti, but I need to find someone in my area that can put it on a scope and watch it warm up while driving on a dyno. I thought fixing those bad grounds would surely have helped it, but it must have helped something that doesn't have anything to do with the way the car runs, because it didn't change a thing!
P.S. It feels like the ignition and injectors go intermittent for 3 to 5 seconds and the tach actually bounces like the power is shutting off. then it drives normal till I shut it off and cool it down again.
P.S. It feels like the ignition and injectors go intermittent for 3 to 5 seconds and the tach actually bounces like the power is shutting off. then it drives normal till I shut it off and cool it down again.
Last edited by Klondike; Aug 23, 2010 at 04:22 PM. Reason: add info
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 23,242
Likes: 117
From: San Antonio Texas
I've got 4 brand new ones.(Bosch) I didn't think it would run with them unplugged. It will set off the check engine light, but will it actually ever go into closed loop?
Advanced
Joined: Jun 2010
Posts: 91
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From: Raleigh NC
I've never run the vette with them off but I have run my BMW's and MB with them disconnected for tuning purposes or when trying to diagnose a problem. It's worth a try since you can duplicate the problem it should be a one shot deal, either it dies or it doesn't.
They basically send a small voltage signal (millivolt ) to the control unit but not until they are well up to temperature which is not the same as engine temp. Typically you need to run a few miles to get them really to their operating temps.
They basically send a small voltage signal (millivolt ) to the control unit but not until they are well up to temperature which is not the same as engine temp. Typically you need to run a few miles to get them really to their operating temps.
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 23,242
Likes: 117
From: San Antonio Texas
I guess it's worth a shot. I can predict within a hundred yards of where this little glitch happens if I go the same direction after I leave the driveway. Even if the check engine light comes on, I'll know why it is lit because I'll be looking for something else anyway. That would confirm if the O2's coming up to temp were related to the problem. It does sound like a computer hand-off problem of changing from open loop to closed loop at a set temperature.
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Instructor
Joined: May 2010
Posts: 235
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From: Southern Colorado
I think that the thought of an issue happening as it goes into closed loop sounds correct. The O2 test may show that if it prevents it from entering closed loop.
The larger question is what the heck is it?
Did you say that it happened as you were letting it warm up before going down the road?
Stupid question. Any codes?
I found this post interesting http://www.automotiveforums.com/t511544.html
The larger question is what the heck is it?
Did you say that it happened as you were letting it warm up before going down the road?
Stupid question. Any codes?
I found this post interesting http://www.automotiveforums.com/t511544.html
Last edited by PreynMantis; Aug 24, 2010 at 12:32 PM.
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 23,242
Likes: 117
From: San Antonio Texas
No codes! The other day I let it warm up (get hot) to 230* in the driveway just to see if it would shut down or stumble while not driving. It went all the way till the fans came on and no problem till I hit the throttle and reved it to around 3000rpm. I stumbled and misfired just like it does when I drive it, and just like always it only lasted for a couple of seconds and then it clears up for the rest of the drive time. It only seems to happen during the warm-up cycle, but it scares the crap out of you every time. I never know if it is going to come alive again or sputter to a dead stop in the middle of the intersection!
If it would die and stay dead, maybe I could track this glitch down.
If it would die and stay dead, maybe I could track this glitch down.