positive ground?
10-14-2008, 07:21 AM
#1
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Join Date: Sep 2008
Location: Norcross, GA
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positive ground?
Is my 83 280zx NA supposed to be positive ground? I ask because connecting a multimeter with red lead to red battery cable, black lead to black cable results in a reading of -14 volts, while red-to-black, black-to-red, gives a reading of +14 volts. ALSO, my timing light has to be hooked up in the same "backwards" way in order to function.
Is there something weird going on here? The FSM says on page EL-25 that ground polarity is negative. Everything runs fine.
Is there something weird going on here? The FSM says on page EL-25 that ground polarity is negative. Everything runs fine.
10-14-2008, 07:29 AM
#2
The 280zx is negative ground.... 99.9999999999999999999999% of all cars are negative ground. Follow the negative battery terminal & the wires will lead to body or engine grounds. Sometimes people don't pay attention and use red for battery ground, and black for positive.
10-14-2008, 07:44 AM
#3
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Location: Norcross, GA
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Thanks, that makes sense. I'm sure that's what's going on here, I'll trace the wires when I get home. For some reason I got it into my head that red HAD to mean the non-ground connection...
The timing was set at about 24 degrees BTDC @700 rpm(!). Is there any reason the PO's mechanic would have done that? It didn't seem to ping, but it seems a lot more "normal" sounding now that I set it to about 10 degrees.
The timing was set at about 24 degrees BTDC @700 rpm(!). Is there any reason the PO's mechanic would have done that? It didn't seem to ping, but it seems a lot more "normal" sounding now that I set it to about 10 degrees.
10-14-2008, 07:52 AM
#4
24* is extreme for the n/a. Maybe the mechanic was thinking it was turbocharged (stock turbo timing is 21*-24*). Shady runs his n/a at about 15* if I remember correctly. And he's got some wild modifications to go along with it.
Did you disconnect the vac advance when adjusting the timing?
Did you disconnect the vac advance when adjusting the timing?
10-14-2008, 07:59 AM
#5
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Location: Norcross, GA
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Yep, I disconnected the vacuum advance. That was the only thing I could think of too, was that he looked up the turbo timing spec.
Thanks for the help, I have to get around to putting up an intro post. This has been a great car and a great board for learning the ropes...
Thanks for the help, I have to get around to putting up an intro post. This has been a great car and a great board for learning the ropes...
10-14-2008, 08:08 AM
#6
Big Poppa
Join Date: Jan 2005
Location: Mission, British Columbia
Posts: 4,499
your neg. 14 is cause the leads are switched at the box. lol maybe, or you have a cheap meter. unless some genius has rewired it like a freightliner of the 70's. ive had mine up to 20 deg for track days, and yeah bout 15 for the street. right now im trying to conserve gas money for the racecar and new 2 bay shop, so its at 11/12ish.
10-14-2008, 08:52 AM
#7
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Join Date: Sep 2007
Location: virginia
Posts: 4,617
Originally Posted by NismoPick
The 280zx is negative ground.... 99.9999999999999999999999% of all cars are negative ground.
Last edited by KasbeKZ; 10-14-2008 at 08:57 AM.
10-16-2008, 11:38 PM
#19
More Than Meets The Eye
Join Date: Feb 2005
Location: Mesa, Az
Posts: 5,120
Originally Posted by snwbrderphat540
lol steal..... damn thats funny
also, joy ride has super sexy paul walker in it
and it wasnt a scary movie, was ok to watch. and truckers smell
also, joy ride has super sexy paul walker in it
and it wasnt a scary movie, was ok to watch. and truckers smell
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