I pulled my tach out to swap the resistors so my tach reads right with the 1J (it's been off by about 200rpm and it's annoying me) and it looks like my tach has different resisitors than I was expecting to find. My car came with a 7MGTE and an automatic transmission. There's also a second circuit board for the ECT power/econ lights that has one wire that goes over to the tach board. Does anyone know if swapping in the 1JZ resistor values will work on a car that came with an automatic?
Tach resistors
- Thread starter destrux
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how do you know its reading incorrectly? Mine was a na automatic. I put a turbo tach in and it works fine.
The tach on my dyno and my AFC Neo both read 200rpm higher than the dash at 3000RPM (it's progressive, it's worse the higher you rev). I hit the rev limiter with the dash tach saying about 6500. This isn't revving fast, so I know it's not just the tach being too slow to respond.
I had an 88' N/A W58 tach sitting here, so I took the circuit board off the Turbo/A340 tach I had and put it on the NA tach (I did this to get rid of the ECT lights) and I swapped out the resistor that was in the turbo/at tach for the 100K resistor that the 1JZ tach has in it. Now the tach reads 400RPM high at 3000RPM and the rev limiter hits when it displays over 8,000. So that didn't work.
I guess I'll have to play around with resistor values to see what I can do.
I had an 88' N/A W58 tach sitting here, so I took the circuit board off the Turbo/A340 tach I had and put it on the NA tach (I did this to get rid of the ECT lights) and I swapped out the resistor that was in the turbo/at tach for the 100K resistor that the 1JZ tach has in it. Now the tach reads 400RPM high at 3000RPM and the rev limiter hits when it displays over 8,000. So that didn't work.
I guess I'll have to play around with resistor values to see what I can do.