No Tach Signal

[talon212]

I have a 95 tsi 4months ago i had the first gen 7bolt swap on it after i crankwalked. After the installation was completed i was driving home and the tach signal and speed siganl would flutter then stop, then do it again. After awhile it was dead signal for about a week then one day the speed signal came back on and not the tach. Now during this time i bought a brand new computer cause i thought it was the problem(it didn't work). Also during that time I had no afc2. I can see my rpm signal through my logger but not on the dash nor the AFC2.
HELPPPPPPPPPPPP!

 

[Old Mitsu Tech]

Pretty rare, but if you can run the engine and the logger can see tach signal, then likely it's the tachometer itself.

 

[talon212]

So basically I should replace the circuit board in back of the odometor gauge cluster. Cause when I call mitsubishi and I described the problem for him, he said it sounds like the a curcuit took a dump.....i'll change it tomorrow or friday and let you know if it is fixed or not...thank you for your time..........

 

[talon212]

I got the gauge circuit board and installed it. It didn't fix the problem so next thing i'm going to do is change the tachometer itself. I will keep you guys posted,wish me luck..

 

[talon212]

I change the instrument cluster 3 times and still the same problem. If anybody has any suggestions please reply. Every night if go outside and read the ohm load signals off the crank and cam sensor, and they are all within spec. HELP

 

[talon212]

I fixed my tach by swapping out my power transistor with one that was laying in my electronic section in my garage, somehow the transistor shorted out. Problem fixed!!!! But however I will look in to why my 1 year old transistor shorted out....I hope this helps some of you guys and gals.....

 

[ixsaves13]

so i've been searching for a used 91+ power transistor to do the mod from here http://www.dsmchips.com/1990ecu.html ... I was wondering... if the transistor is bad, wouldn't it not only stop your tach from working, but also cause other problems with ignition??

 

[luv2rallye]

I was wondering... if the transistor is bad, wouldn't it not only stop your tach from working, but also cause other problems with ignition??

The power transistor unit has a special tacho circuit in it for the tachometer signal only. If this was bad you will have this problem as the power transistors are separate from it and can be operating perfectly.