Tach not working?? help

[Asimmons90GSX]

Well recently we just put my brother's motor into my 1990 Laser turbo chassis. When I parked the car about 2 years ago ALL the guages worked perfectly fine. So when we went to fire up the car we noticed the tach was not moving. Reving made no difference. We do have the MAF translator setup on his car so we checked where we tapped for the rpm signal on the cam angle sensor and everything was fine. Nothing changed. So then we tried another guage cluster and got the same result. So what could be causing the tach not to work? I've heard of broken tach's on 1G's but never have researched enough to know how to fix it. Any ideas??

 

[pj91gsx]

I have read up on tachs not working because I thought it was my gauge clusters. I have 3 gauge clusters. The tach was on and off working. I read that the transistor is where the tach signal is. One guy on here a loose wire on his transistor that was not making it work.

 

[Asimmons90GSX]

where is the transistor located?

 

[motrmaniac]

its by the fuel rail. i acutaly had the same problem about a week ago where my tach decided to stop working.. the red wire i think i dont remember was loose inside the clip and casued the tach to stop working.

 

[pj91gsx]

More specifically on the timing belt side of the engine. Its bolted to the intake manifold under where your plug wires flow threw.

 

[Asimmons90GSX]

Ya ok I know what your talking about. I'll check that out and see if I can get that thing to work. Thanks guys

 

[thatblondechik]

Did your tach stop working RIGHT after your translator install?

Mine did the same thing.

The translator pulls a 12v signal but the tach signal only provides I think a 9v signal (someone please feel free to correct those if they're wrong!)

I'm unsure of the exact values. But it's because your translator is pulling all the signal for your tach. It doesn't matter if you tap in at the ECU or the transistor.

 

[luv2rallye]

The 90 has a tach noise filter and is different than all other years.
http://www.dsmtuners.com/forums/problem-diagnosis/147266-1990-tsi-tach-question.html.
90 -> 91 Tachometer differences

 

[Travi2506]

Are the other gauges working? (oil pressure, fuel, temp?)

 

[93_tsi_fwd]

did you try looking at the fuses under the dash?

 

[blownturbotsi]

But it's because your translator is pulling all the signal for your tach. It doesn't matter if you tap in at the ECU or the transistor.

The translator only gets an RPM signal from the CAS for the "RPM based tuning" function. I used to run my car without the signal wire with no problems.

 

[Travi2506]

did you try looking at the fuses under the dash?

That's why I asked if the other gauges were working... been there done that. Mine wasn't a blown fuse, just a loose one. Try wiggling it and the needles should jump, if that's the problem.

 

[thatblondechik]

The translator only gets an RPM signal from the CAS for the "RPM based tuning" function. I used to run my car without the signal wire with no problems.

+1
Which is exactly why I disconnected it.