I have a question. Lately when im on the road and i stop at a light, sometimes i notice the RPM hand go down and up a bit.. what could this be?

 

If you go to the rear of the car(at idle) do you hear a slight miss from your exhaust?

 

a/c kicking on and off?
could be a bad neutral switch

 

No, I dont ever use my ac...

 

Im starting to wonder if the Spark plugs could be the cause...

 

when was the last time u changed ur coils and sparks then ?

 

I havent changed any internal engine parts since I bought the car, which I bought with 47k on it, now Is about to go into 50k,

 

Hmm, do u know if the previous owner changed it at all ?

Its important because, if the previous owner has NEVER changed them, you should change it out ASAP.

 

Tachometer - an instrument that measures the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analog dial, but digital displays are increasingly common. The term comes from Greek Ταχος, tachos, "speed", and metron, "to measure".

 

Sorry to threadjack here, but a sort of related question...

Can you do any damage to a rotary motor by not changing the plugs every 10k miles? I know this is the suggested protocol, but if you wait until you start to see the signs of deteriorating plugs will it cause any harm? Other than possibly flooding the motor?

Also, is the spark plug life expectancy shorter on the rotary motors due to the oil consumption?

 

/\ 10k might be a tad overkill.. 25k or so you will need to check them over though.
if the ignition system is not up to snuff you're not combusting completely and that will lead to carbon buildup.

 

You can under normal conditions (NA engine) get 30-35K miles out of the OEM-NGK plugs. We have had some cars here go over 50K but you will feel some hesitation when they get worn. If they are the cause of the engine miss firing then you have gone as far as you want to go! Rotary engines fire more often thats why they ware out sooner.

 

Thanks for the explanations

I have been wondering because I am having some long starts and according to the local stealership they have already performed teh TSB relating to this. I have been considering changing the plugs, but the car seems to be running perfectly fine ATM

 

Long starts can also be attributed to the ignition coils.

 

I had considered that as well, was hoping that those had been replaced with the TSB, but I am doubtful. Are the coils difficult/expensive? to change?

 

The coils are $25-30(each and there are four of them) and easy to change, a good time to do the spark plug wires too( I got the OEM ones for less then sixty dollars.......

 

I had the samething. Time for a tune up man. Get new coils spark plugs and spark plug wires. Save your self the money and change them your self. I changed them all in about one hour. Not bad.

 

It is very easy to change the plugs and the coils BUT be sure you have someone around with you who knows what they're doing the first time. If you mess up, it's not pretty. Gotta watch the leading trailing thing VERY carefully. But it's not complicated.