Tachometer issues

[nelson20]

Hi there,
My tachometer jumps around and/or just goes dead. I've figured out that it only does this when my A/C is turned on. When the tach flickers and/or goes dead I feel a slight loss of acceleration as well. I've been doing some reading here and it seems that my distributor could be causing this? Just wanted to confirm that with ya'll?

Second question is, if it is a bad distributor, can I be causing any further damage to anything (like A/C compressor) running like that until I get it fixed?

Thanks!

Kelly
89 SEi 4dr 5spd

[russiankid]

I don't see any damage that can be caused unless the car miss-fires. Don't take my word for it though, someone will chime in with better knowledge.

As far as A/C, no damage should be done to the A/C compressor.

[2drSE-i]

It can be caused by the distributor, yes. Check all the connections to that, all the wires going into it, etc. Your A/C shouldn't be affected.

[2ndGenGuy]

The distributor in my 81 caused those problems exactly as you described. If you have a known good dizzy to swap to test, it can't hurt to try it.

[lostforawhile]

the tach reads off the negative side of the coil. the pulses to the coil are triggered by the module in the dizzy. if that module is going bad, it can cause the tach to do wierd thing,yet the engine still functions. it's just not recieving a clean square wave signal at the coil. one symptom to watch for in the three g is it cutting out when the engine warms up,then when it cools down, it starts right back up and runs fine. the module gets sensitive to heat. there is a factory engineering defect in these modules, they are exactly like early model ones,as a matter of fact you can swap them and vise versa. i ran one from an 81 civic in my three g for years. on the early cars there is a dire warning about making sure there is heat sink grease on the bottom of the module,to conduct heat away. yet guess what? same module design on the three g,yet, the module is sitting on aluminum spacers which prevent heat transfer through the module base, so they have heat problems shortening thier life. this explains why i have modules from 80-81 that still work fine,yet my original module from the car has failed .as well as a replacement.

[nelson20]

Thanks for responses... I don't have an extra one, so I'll try and pick one up from the junkyard. Hopefully they aren't too spendy since I have $237,000 worth of other repairs to do. Thanks again.