ok for some reason my tach won't work on my 1991 camaro rs 305 TBI that is standard. i took out the gages the contacts look good. I believe the signal for the tach gets picked up on the coil. would there be a wire run there for the tach. how do i fix the tach. or should i just buy new gages? to solve the tach problem. the fuel gage also doesn't work which is a real pain.

 

Is there power to the instruments?

 

Yeah there seems to be power cause the rest of the gauges work. when i turn on the car the tach goes all the way up and then never comes down till i turn the car off again. the gas gauge just bounces around or if its full it will just stay at full for a long time.

 

It soulds like the tach is getting full 12V power instead of the signal from the negative side of the coil. Check the connections at the coil/distributor to make sure they haven't been inadvertently connected wrong. Is this a factory ignition or is there some sort of CD box installed (like MSD)?

The fuel gauge is probably lacking a good connection or ground at the sending unit.

 

thanks for the info. Its just all factory no msd. Do you know where the sending unit would be for the fuel gage. is it easy to get to. or is it something where i would have to take off the fuel tank to get too? thanks again erik

 

Hey buell, my tach does the EXACT same thing you describe. Do you run a stock coil? When i bought my car it came with one of those huge Accel coils with some sort of adapter that hooks to the stock wiring harness.

Its on my list "things to fix" but its not anywhere near the top. If you find the fix can you please post it here? If i figure it out first i will let you know.

 

Hey, I believe it is the stock coil, but it could be aftermarket now that your telling me your having the same problems. maybe i just need to buy an adapter or something. It could be unpluged idk. I'll have to check it out today. I post if i get it to work.

 

alright i just looked at it played around with the wires. all the wires are pluged in and secure. now what im thinking it could be is the distributor cap. what does anyone think. good idea to get a new one. I was thinking of getting an accell cap. will that work with the stock distributor?

 

The distributor cap has nothing to do with the tach. All it does is transfer the spark from the coil to the plug next in line. Its whats under the cap and rotor that is in question.

 

Cap would have nothing to do with it. I replaced mine yesterday for a tune up. Aside from the car running alot better, tach is still at 7k.

 

The tach being buried, last time I seen this fixed, I put the pedal to the floor. Note: use at your own risk, the stock tachs are usually off anyways. FYI.

 

Sell the mustang and get a instrument cluster off of ebay.

 

Yeah i tried to sell the mustang got **** for it on ebay. so i keep it and the wife drives it. back and forth to work. I looked under the cap and the rotor and underneath it looked rusty in color. so it could be the distributer then. Thanks for all your help.