I know there's a big thread above about fixing problems with the tach but it's a little above my skill level and I'm not convinced the problem I'm having is with the board in the cluster.

My issue is that when I start my 91 camaro the tach goes all the way to the right (pegs) when I start the car and stays that way. I don't think the board is the problem because I have another cluster that I tried and it does the same thing. I suppose it's possible that two clusters could have the same problem but I'm doubtful.

I'm thinking there's a sensor somewhere on the engine that sends a signal to the cluster and maybe that could be the problem? Where would this sensor be? Any thoughts or advice is appreciated.

Thanks in advance!

 

I guess it's not that far off my skill level and I can test the continuity on the cluster I've got out and make sure that I do or don't just happen to have two bad tach boards. Skill curious about where the sensor is that sends the signal though.

Thanks!

 

There is no "sensor".

The tach looks out at the – side of the coil, and does its thing based on how often the module fires the coil. Pretty much Stone Age.

If you have any kind of a multiple spark discharge ignition such as MSD but don't have the adapter for the tach, it'll do that.

These tachs fail by reading high, often WAY high; but usually they'll at least be on the scale at idle.

Fixing them doesn't take much skill. Pretty basic, really, if it comes down to that.

 

Yeah, I don't know a lot about cars but I'm learning. How would I know if I have a multiple spark discharge ignition?

I just bought this car over the summer and the tach didn't work then and from what the guy told me about it, the fuel injectors where replaced recently if I remember correctly. Maybe this ignition system was added as well? I have no clue.

Thanks so much for your response!

 

I tested the board and I have no continuity between pins 4 and 10. I guess I just happen to have two clusters with bad boards. I read some of the thread above about the fix. Anyone know what size resistor I need to use for the 6 cylinder engine? I'm sure it's in there somewhere but maybe someone would be kind enough to save me some time and tell me before I go looking for the answer?

Thanks