Where's the grounds?
Melting Slicks
Joined: Apr 2004
Posts: 2,008
Likes: 38
From: Space Coast Gator Territory
In addition to the starter ground on the passenger side and #1 body mount clipped on the body to frame channel; there is a ground on each exhaust tube before passing through the portholes in the crossmember. I have no idea what your problem is, but a ground failure will certainly cause one.
Drifting
Joined: Nov 2002
Posts: 1,665
Likes: 1
From: Ontario
With a voltmeter you should measure zero volts between the engine block and the frame. If you measure anything else check your ground cables, the tightness of the lugs & bolts and the cleanliness of the contact points.
Burning Brakes
Joined: Sep 2004
Posts: 1,167
Likes: 2
From: Ft.Worth Texas
In the dark, with engine running, where do you see arcing? Move wires around a bit with a non metalic stick and watch for an arc. Like someone else said, battery voltage will not arc, however it could spark if a wire was touching a ground.
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 6,128
Likes: 21
From: North Alabama
Originally Posted by David Ey
In the dark, with engine running, where do you see arcing? Move wires around a bit with a non metalic stick and watch for an arc. Like someone else said, battery voltage will not arc, however it could spark if a wire was touching a ground.
Checked the engine to frame ground and battery to frame ground. Both are clean and tight.
Pro
Joined: Oct 2004
Posts: 567
Likes: 0
From: Springhill Kansas
Originally Posted by Jclgodale3
do not see the arcing "while" engine is running. Only during startup.
Checked the engine to frame ground and battery to frame ground. Both are clean and tight.
Checked the engine to frame ground and battery to frame ground. Both are clean and tight.
Racer
Joined: Jan 2005
Posts: 389
Likes: 1
From: Sarasota Florida
Check that ground from the starter area of the wiring harness. I have bought two vettes in the last year, both had that ground on the starter motor instead of being clamped to the bellhousing bolt. My buddies vette had the same problem.
Pro
Joined: Oct 2005
Posts: 505
Likes: 8
From: Houston Tx.
One thing to look for on ground connections is the lack of or misplacement of the star washers that go between the cable and the frame. Too many times, I've seen people put the washers between the cable and the bolt head and it doesn't work.
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Advanced
Joined: Jul 2004
Posts: 72
Likes: 0
From: Houston Texas
Assuming that your engine block is properly grounded, and it sounds like it is. Then it is concievable that there is an inadvertant connection to the pedal bracket assembly to some circuit. Power could then flow from the brake booster to ground which just happens to be the dip stick. As I recall that bracket assembly and everything connected to it are not grounded anywhere.
I would suggest that you place a voltmeter between the engine block and the brake booster and see if you are reading any voltage while cranking and when running and stopped. If so look for a circuit that is making contact with the metal brakets somewhere. It could also be in the steering column and all the switches and wires that are associated with that.
I would suggest that you place a voltmeter between the engine block and the brake booster and see if you are reading any voltage while cranking and when running and stopped. If so look for a circuit that is making contact with the metal brakets somewhere. It could also be in the steering column and all the switches and wires that are associated with that.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Originally Posted by Jclgodale3
do not see the arcing "while" engine is running. Only during startup.
Checked the engine to frame ground and battery to frame ground. Both are clean and tight.
Checked the engine to frame ground and battery to frame ground. Both are clean and tight.
Additionally, regarding above from s car go...can you tell if the spark is jumping from the booster to the stick or the other way around?
Last edited by kb2fzq; Dec 18, 2005 at 09:23 AM.
Instructor
Joined: Jul 2000
Posts: 221
Likes: 30
From: columbia mo.
You say the spark only jumps when trying to start, but doesnt when running. I would recheck all grounds just to be sure. then might try replacing starter. wouldnt think that would cause the problem but crazer things can happen.
Melting Slicks
Joined: Mar 2005
Posts: 2,095
Likes: 299
From: Midlothian VA
Originally Posted by GTENIT
You say the spark only jumps when trying to start, but doesnt when running. I would recheck all grounds just to be sure. then might try replacing starter. wouldnt think that would cause the problem but crazer things can happen.
I have to agree with kb2fzq - I doubt you're getting a 12v spark to jump any gap much less a 1/8" gap.
However; Something else to consider:
You say it only sparks when starting but not while running.
Should you car be wired correctly (this is, it's in "non-bubba condition") then the ignition coil is getting 12 volts during the starting process vs. the @8 volts it gets while the car is running. This higher voltage could/should result in a hotter initial spark (to aid starting) an could indeed cause your spark plug wires to arc during the starting process but not while running. May not be the answer but food for thought.
Last edited by Hammerhead Fred; Dec 19, 2005 at 12:49 AM.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Originally Posted by shafrs3
If the coil is still in question, try disconnecting the coil and cranking the engine to see if that eliminates the arc.
(very good shafrs3
)
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 6,128
Likes: 21
From: North Alabama
Originally Posted by shafrs3
If the coil is still in question, try disconnecting the coil and cranking the engine to see if that eliminates the arc.