Rob delta

83 Delta 307 cu.
So I decided to put in a small tachometer so i could see what the engine was doing. I got a sunpro mini 2 5/8" tach and I was able to fit it flush into the dash directly to the right of the steering column. I wired it up correctly including a good ground. It worked just fine driving around on a couple of short trips so I put the dashboard back together.

Here is where the trouble starts: After driving for around 30 minutes functioning normally, it then will hit a high point and not drop below that. It keeps increasing past this value as the engine revs higher and again won't drop below that. When i shut the engine, it does go back to zero. But the problem still exists if the engine is immediately started back up. The tach works normally again if the engine has been off for a while. Starting the engine after sitting an hour or so, this cycle repeats.

Has anyone ever heard of this? Could it be a bad signal from the coil or possibly the ground has interference? A charge building up inside the tach itself, thats why it works for a period of time then acts up?

Thanks for any responses
-Rob

Allan R

Sounds like you have a defective tach. Call up sun pro first and ask them the same question. If they can't give you the answer, go see the dealer where you bought it and tell them you want it replaced under warranty.

MDchanic

Agreed.

Your tach is bad.

Take it back.

- Eric

Rob delta

Well I emailed sunpro last night, they told me to double check the ground. I just emailed back giving the detailed description i just posted here. I just have a feeling they will jerk me around and claim it's not the tach itself. I was planning on calling sunpro directly to see what they have to say.

Allan R

Don't let them jerk you around. If you had a bad ground the tach wouldn't work - period.

Rob delta

Yeah, I bought it from everyone's favorite store, Auto Zone. They told me i have to go through sunpro for a replacement. Bet it would be easier to just walk into auto zone and tell them I want a refund because the tach won't fit or something.

AZ455

I'd try that. I don't know about your AutoZone, but we have two in the area, and they'll take anything back. I've heard of the one in town taking items back that were bought at Napa or O'Reilly.

MDchanic

Just go there with the tach, the box, and the receipt and tell them it doesn't work and you want another.

- Eric

oldcutlass

This is what I would do!

Rob delta

I contacted sunpro directly. They are sending out a new tach. They gave me a shipping order number, so hopefully it will be arriving soon

Allan R

Good for them. Obviously the followup call made a difference. Hope the new one works!