Tach problems

[white92talontsi]

I swapped Instrument clusters in my 90. Main reason was my oil gauge went bad and another was so the mileage would match with the motor that I put in the car.
My car is a 90 5 speed.
Cluster and engine came out of a 92 auto AWD.

Tach worked fine before in the 90.
Tach also worked fine in the 92 while I was driving it before i pulled the engine.

So I swapped to the 92 auto cluster and the tach no longer works. What are the differences??

Tach filter Is plugged in and bolted to the intake.

 

[Brentenorris]

this is kinda time consuming. i put a 91 cluster in my 90 but this is with a 91 ecu 91 coil pack and a 91 igniton module or the seven wire plug right beside where the coil pack is. ### all did u take off the 92, because i had to use the filter wire that runs to the ecu from the ignition module to get my 91 tach working which usally comes from the 90 coil pack noise filter

 

[white92talontsi]

I am using the 90 coil pack and transistor and the 92 cas. Still have the 90 tach filter hooked up. 90 tach worked fine but 92 don't.

Sent from my SPH-D700 using Tapatalk

 

[Brentenorris]

im not for sure but i think you will need the 92 transistor, coil pack, and ecu to use the 92 tach when i did my 91gsx to my 90 tsi i had to use the transitor, coil and ecu from my 91gsx the 92 tach gets the signal from the transistor which you still have the 90 transistor

btw i still have the 90 tach dont know if it works but im trying to sell it

 

[steve]

I am using the 90 coil pack and transistor and the 92 cas. Still have the 90 tach filter hooked up. 90 tach worked fine but 92 don't.

Then you need a 90 cluster. The output from the 90 tach gate on the coil pack produces a different signal from the one a 91+ power transistor generates.

 

[91darkdsm]

not trying to jack this thread but i have a ? i have been doing countless research and cant find an exact answer. first off my tach seems way off to me. examples, 2nd gear wot pull to 60mph tach only reads 4000 rpm, 5th gear steady driving at 60mph, ive changed plugs and coils. tach has read like this since i purchased the car. also my obd1 port by the ecu has been cut out i dont throw any cel and was wondering if this has anything to do with the tach issue. sorry for long post just wana get this fixed. its driving me crazy

sorry 5th gear steady driving shows 1000 rpm at 60 mph

 

[Brentenorris]

I would suspect the cluster being the culprit. I would still make sure nothing is grounding out or touching at the obd port and maybe wire a new port in