Today at 5:00 AM I was awoke by my dad calling my phone from my car asking me about these two beeps he kept hearing. Having gotten slightly over 4 hours of sleep and only just being woken up, I told him to bring it home and drive his car instead. While I'm saying this, I'm getting to the FAQ and find what I'm looking for. I call him back and ask if the tach is working, he says "No." I tell him to restart the car and blamo, it works! It was funny, I automatically went to the boards without even thinking.

So anyway, back to my question. Why is it that every once in awhiile my tach just won't work? Just maybe once every 30-45 start ups. Which wires are for the tach, too?

 

This might be an indication your trailing coil pack is having problems.
The tach gets its signal directly from the trailing coil pack.


-Ted

 

my car is having a similar problem , the tack will be jumping before it starts up then stop working and go all the way down to 0 when it starts up , but then if u shut it off and turn it on it will work again

im also having problems with my car reving after being warmed up, would these problems be related ? ( this is in another thread)


im hoping to get the diagnostics done and figure out if it is throwinga code

 

I went through this, and after reading the boards for hours on it; though it can be the trailing coils failing it seems it is more often a bad ground or lack of ground from the engine that was causing it for people. That's what the problem was with mine. The guy that did my clutch left both the stock engine grounds dissconnected yet it still worked most of the time.

 

i did my engine wiring myself and every ground was connected/bolted down so i know thats not what it is

 

IF you have confirmed that your trailing coil works and your tach still intermitently functions, take a look at your starter or battery.. when you start the car, the tach should move, however if the car is turning over slowly (because of a bad starter, or weak battery) and it still manages to fire up, chances are your tach will briefly go to 1000rpm, then just drop to 0.. The stock ECU needs to see a min crank speed.. if it does not get this min crank speed, then it will shut the trailing coils off and your tach will die... sounds strange, but I confirmed this back when I was running a stock ECU and had a starter motor that was slowly dieing and would turn the motor over under 200rpms.. my tach would blip up and down as I turned the motor over.. as soon as the motor fired up, the tach would go to 1000ish rpm, then about a second later, it would just drop to 0...

 

mine will do it on and off, like it will shut off after the car starts then ill shut the car off and start it again and it will be fine... i dont know what the deal is... maybe my trailing coil is going bad im going to get it checked out soon

 

I'm having a similar problem. However, when my tach spikes wildly, the engine is also popping, like the exhaust is backfiring, then suddenly the tach dies, I hear beeping, and if I park my car for a while, the battery is dead. I've replaced the alternator and recently, I had my rusted broken exhaust repaired (it broke behind the cat, so I had new piping ran from the cat, back). Also, my car overheats like mad. I think my car is very near death at this point. I'm going to try to replace the water pump and check out the trailing coil pack.