DCmina

Uhh, when I let the car idle, the RPM meter goes up and down from 0 to 1000. It's at 0, then go at 1000, then comes back to 0 etc...

Whats wrong with my car? I'm scared!

Thanks!

HWO

does the engine increase speed at all or is it just the rev counter itself?

DCmina

And it's just the RPM meter, the speedometer stays at zero.

niner

my tachometer was actin funny for a while then it just quit working and the check engine light came on. it set off the code for the trailing coil, turned out to be a bad ground.
might not be your problem, but perhaps

rx7grl

i have this problem when i start the car, but if i press the gas one time before i start it it doesn't do it so drastically, it will only go between 500-700 or so, it doesn't fix it but i notice that it isnt so drastic. Hope that helps. I don't know if you meant when you started the car or not.

soulfisher

Same type of problem with my rev counter found it to be a low battery? ....after recharging battery- problem went away , but this could still be due to a poor connection as the extra charge from battery may of over come a poor connection giving low voltage/amps at low battery power?

gerbraldy

my tach won't turn on when I start my car in the morning. After that, it will come on every time for the rest of the day. Then the next morning, the same thing, happens everyday.

mycarisolderthanme

RPM thingy = tachometer...

unless your trying to be cute or something.

when your TACH goes from 0 to 1000, can you hear the motor revving as well? or is it just the readout?

Ol-Skool

I have the exact same problem!!! Pisses me off to no end..

Every time i start it now it does it, wont register on the tacho and you know the car isnt running right, my thoughts is it might be one of the coils on its way out? The car doesnt rev smoothly, but the way i get it to work is rev it till about 5 grand and then flick the headlights on and the tacho fires up and comes to life, then its fine for the rest of the day!!

Meh i only drive my car once a week if that, ill live with it for now :P

KompressorLOgic

iTrader: (6)

my tach started to do that when the signal from the trailing coil was grounding out.

Ol-Skool

Same as my symptoms?

Ill have to check the trailing coils out, pretty sure the problems lies there somewhere

Ice_Wolf

Wait a minute, if it was going between 1000 and 0, when it hit 0, wouldn't the car stall? 0 means that the engine isn't spinning at all, meaning it wouldn't be running. So I'm thinking it's gotta be something electrical? On my Cavalier, the engine would rev up and rev down at idle, and also it woiuld sometimes just stall on me when I pushed in the clutch. Turns out the cells on my battery were all incredibly close to dead. Also, my speedomoter would act funny to and jump around when I pressed the brake. Definitely check your battery cells if funny things start happening with your car.

Rxmfn7

iTrader: (4)

Or.....dont drive a cavalier.

Sorry I had to

KompressorLOgic

iTrader: (6)

well mine was doing that when i was tring to hook up a shift light and i conected 1 of hte wires to the trailing coil signal wire, the extra 1, and i accidnetly let that wire hit ground while the car was running! and my take started freaking out go down and back up.

so somethings prolly grounding out or the gauge is going bad?

Ice_Wolf

Hey! It's called a daily driver.

KompressorLOgic

iTrader: (6)

the rx-7 is a daily driver, but its also a daily breaker.... lol... keeps me busy tho!