Tach/Boost gauge waaay off????

[tpabayflyer]

My 87GN shows about 5,000rpm and 5psi boost when cruising the highway about 3,000rpm(estimated) and pulling 10" of vacuum on my boost gauge..... What is causing the factory gauges to read so far off??? tia TBF

 

[77tech9]

18 years of age.

 

[turbo nasty]

Normal one of the common GN turbo regal things.

My 87 is like 800 rpm off.
my 86 it is waaaay off at idle the tach is fully illuminated and the boost meter also.

 

[tpabayflyer]

I was wondering if there was a quick fix or something for this but its not a big deal.... my vacuum/boost gauge is a mechanical unit and works great and I really don't need the tach but it would be nice if it worked.. TBF

 

[Mightysix]

Dont fell bad mine is Fudged up too

 

[fitz3820]

You can send your dash unit to Casper's Electronics and they will calibrate it for you.

http://www.casperselectronics.com/cgi-local/store/commerce.cgi?product=SVC

or http://tinyurl.com/28c35

I have been too lazy to do this and I hate the bar graph anyway.

Mark F. 87 GN 11.9 @ 115

 

[turbo nasty]

yep...Caspers is the only one I have ever heard of.

 

[87grandnat]

i use my scanmaster as my tach

 

[Daves69]

Caspers is the way to go. The tach boost guage has a resistor network the goes bad over time. Caspers bought the entire stock of spare parts from the O.E. mfgr and has the ability to calibrate the unit.