I'm on my 6th rx7 a s5 TII, sweet ride w/ under 70,000 original miles, one issue though, the tachometer has been acting strange, it would not work for the first 15~20 minutes of driving, then it would work even after shutting the engine off.

Today after driving around the mountains I looked down and the tachometer read at zero.

Anybody had the same issue? what worked to fix it? Drives me crazy.

ADDL info: This is an old thread from the PO. https://www.rx7club.com/2nd-generati...check-1000751/

 

Looks like you found your answer skippy!

 

Make sure the trailing coil is bolted to the fender properly as this is how the igniter receives a ground. You need to verify that the coil is actually working. And you can jumper the bullet connector at both coils to each other and the tach will use the lead coil for the tach signal. If the tach works as it should free of problems then you know the tach itself is not the problem and most of the relevant wiring is good.

 

I verified the proper function of both coils, I will check the grounds and cables tomorrow. I can't drive without a tach.

 

If you jumper the bullet connectors from both coils the tach should then work?

 

I took off the coils off my S5 N/A and swapped them to the TII, Nothing changed.
Made sure all coils where firing, No change.
Checked spark plugs, plugs loose, re-tightened, no change.

Swapped out gauge cluster off my S5 non turbo it works

Any body see a problem with this? diferent calibration? I like having a volt gauge since I have an aftermarket boost gauge. I would prefer to keep the TII tach for the proper redline reading. Can I swap out internal parts?

 

Yes, you can.
IIRC, the entire tach is held to the circuit board with three screws, the layout should be the same for both clusters.
The mounting screws are also the electrical connections, so it's pretty simple.

 

TACHOMETER PROBLEM SOLVED

Well, it tunred out to be the tach itself, confirmed by switching the gauge cluster from my N/A to my TII, works great.

I swapped out the tachometer gauge face plate and the speedometer, I like the fact that I have volt gauge now, since the stock boost gauge was useless.

 

God does not need a dam, he can walk on water.

 

hey rxmiles was good meeting you tonight down by micro center! Im sure ill see your t2 around more often! I should be bringing mine out within the next few months after paint and boostleaks are fixed!

 

Hey, man it was nice talking to you a well. I'm looking forward to seeing your rx7.