Digital Tach Question!

[gold69charger]

I just bought an 87 Grand National and the Tach is off. It is reading 1600-1700 RPM, but is actually at 1000-1100! Is there a way to adjust the Digatal Tach? and if so can anyone help me on how to do it?

 

[Tony87gn]

Didnt you just sell a Grand National? I thought I saw one for sale by you on autotrader a while back.

 

[gold69charger]

Yes, I did have an 87 GN that I sold. It had 112,000 miles on it and had alot of bolt on mods and no tilt wheel,no power windows,no power seat,etc. The one I just bought is loaded with only 45,000. and all stock! Can you help with the Tach question?

 

[Tony87gn]

No I have no clue about the tach but I just thought i remembered your name.

 

[turbofish38]

There is no adjustment you can do to the tach. Check out this link http://www.casperselectronics.com/cgi-local/store/commerce.cgi?product=SVC

Scroll down to the tach repair/exchange

Eric Fisher

 

[gold69charger]

Thank you very much for the info., that sounds like the best idea.

 

[SuperSix]

They are almost all off, Casper's is the only solution to fix it.

 

[gold69charger]

OK, just got the tach/boost gauge back from Caspers and the tach works great! The only thing is the boost gauge was not working before and it is still not working? What could cause this? Is there a sensor it could be? Any help would be great. Thanks alot guys for your help on the last question hopefully there will be a simple fix for this one aswell.

Originally posted by SuperSix
They are almost all off, Casper's is the only solution to fix it.

 

[SuperSix]

Originally posted by gold69charger
OK, just got the tach/boost gauge back from Caspers and the tach works great! The only thing is the boost gauge was not working before and it is still not working? What could cause this? Is there a sensor it could be? Any help would be great. Thanks alot guys for your help on the last question hopefully there will be a simple fix for this one aswell.

I woul contact Casper's and see what they have to say - I'm sure the dash is fine - may be a sensor.

 

[gold69charger]

The boost gauge did not work before I sent it to Caspers and it still does not work, so that is what I am asking, is there a sensor and if so where is it.

 

[turbofish38]

The boost gauge is controled by the MAP sensor on the right fender. Maybe a bad vacuum line? I'm not quite sure what you check on the electronics side as I 've never had to check the MAP before.

Eric Fisher

 

[gold69charger]

I called Caspers and they said check for cracks in the line and to check that the boost gauge is working correctly you need the disconect the wires to the MAP sensor and there are 3 prongs marked A B C...jump B and C with a paper clip and then turn the ignition on...the boost gauge should light up all the way across. I did this and it did light up all the way across. So I guess it is the MAP sensor.

 

[gold69charger]

UPDATE

OK now that I checked that the boost gauge is working properly, I replaced the MAP sensor and the plastic hose that runs to the MAP sensor....still no boost? Any other suggestions!

 

[gold69charger]

Any help with this one??

 

[turbofish38]

The only thing left to check is the wire harness. It goes through the passenger side firewall by the ECM. Maybe check the connector at the dash cluster for a bent pin or bad connection?

Eric

 

[turb]

Stock Boost Guage

Any fix yet? I have the same problem but haven't done much more than look for vac. leaks with no success.

 

[gold69charger]

I have not messed with it since my last post. I have the car stored for the winter and will look at it again when spring comes. If I figure it out I will post again.