tach

[RagingPanda]

How do you take it out of a 78 280z? I took out the two screws and it just won't slid out. Do you have to take out the dash or is there a trick involve? thank you again

[RagingPanda]

I managed to get it out by pulling the dash. I was trying not to take out the dash but screw it. My replacement dash is broken also. When I turned on the car the needle jumped to 8000 redline. Is there a way to fix it or something else broken to cause the tach to be like that? Or just get a new one.

[evildky]

hm, well IIRC the tach pulls out the front after the 2 scres are removed? been a while, as for the tach at 8k, I guess that means it just mysteriously jumps to 8k while idling and or running? are you running the stock ballast and coil? have you changed the wiring at all? from my experience either they work or they don't, if they jump it's due to some interferance from somewhere

[RagingPanda]

it's a direct replacement from the broken one that I had(stays in one spot, 3000rpm). It jumped to 8000 or all the way to the right the moment you turn the car on so idling or driving don't matter.

[evildky]

uh oh, what year was your donor? they did change the tach trigger signal when they went electronic in 74

[RagingPanda]

i think the donor is the same year as my car, 78

[evildky]

hmmm. everything is stock and unaltered?

[RagingPanda]

as far as i know, yes, but I could be wrong. I put it another tach but this time the needle went up really slow, like a temp gauge. Then it stuck at 2000rpm. I know the tach is from another 78 so what else could cause the malfunction?

[evildky]

wow, thats really odd, to have 3 of them fail all in differetn ways?... you might just have bad luck, there are companies out there that recondition stock gauges, might be worth having one rebuilt? if not keep trying the used ones?

[RagingPanda]

So weird. Today I started the car and the tach worked! I guess it's some loose wire but I have no idea where to start. hahah

[evildky]

it's odd that you got inconsistant results, might be multiple loose wires?

[RagingPanda]

im pretty sure the wires are loose. I think it's because of the heat. It's ok at first but when i drove it for a while the tach stop working so the heat in the engine bay might mess up the already crappy connection. Now it's time to find that connection.

[Pharaohabq]

How is the Tach triggered in a 78 280Z? Perhaps we could wire one up externally to ensure it's not that tach, rather than the wiring? Phar

[RagingPanda]

Been very busy to even attack the problem. I heard that switching to a later ZX distributor might also help with tach issues but I'm not sure.