Since I bought the 92 vert, the tach has only two positions....zero when the key is off and 3,400 rpm when the car is running. If I accelerate hard (like getting on the hiway) it does move to about 4000 and then returns to 3400.... I had assumed that the tach was just bad and needed to be replaced. However, I have read a few references to other issues that cause the tach to act funny, even though it is ok... Could someone enlighten me as to what else to look for...I don;t mind swapping it out, but I would hate to do that and still have the same dopey problem... Thanks in advance....
There really isn't anything else that would cause that (well, maybe a bad ground, but most of your gauges should be messed up if that is it). I would think it is the tach that is at fault. It's a fairly simple system- the tach gets its pulse signal from the negative side of the coil (not sure in the case of the DIS coilpacks, but it would probably get it off the ignition module) and gets key on power to operate. There really isn't anything that would cause an improper signal to it from the ignition module unless the module or wiring harness is damaged, and I think you would have noticed that already.
THanks for the relpy... I was able to procure an entire gauge package from a 93 4 cylinder LX on ebay...supposed to all work perfectly. FOr $35, I'll sure give it a shot...thanks
If the new cluster wont fix it I would look at the harness going to each of your coil packs. I had one break and it only read 1/2 rpms
have the igntion module checked if its a Dual plug car, when the module starts to go bad, the tach can act funny. Dr.