MX-3.com

Ok so a little intro i bought the car about 7 months ago for $500 bucks it has 110K onit runs great no probs, body in good shape.
After about 3 months i started to have fluctuating idle, would go from 1000 to 500 Rpms.
Things iv'e done:
1) New plugs Denso Iridium
2) NEW Wires
3) New rotor and Cap
4)New fuel Filter
5) New COOLANT TEMP SENSOR (Help quite a bit thought prob was fixed but not quite)
6) CAI

So after Replacing the coolant temp sensor the prob. stoped for a few days So I thought.
Now after warming up it will settle at about 700 Rpms but sounds very ruff. it will still occasionally drop a bit almost to a stall but not quite.
Well i am stuck it throughs no codes there is no air leaks, ive done all the tune up stuff and dont know where to go from here, any help would be much appreciated.
I hope i can get this fixed soon cause it is my everyday car.

Other things to try
- Clean throttle body
- Clean Fuel Injectors (add FI cleaner to the gas tank)
- replace pcv valve (for rough idle)
- Add a ground kit (if idle gets worse with electrical loads like radio, lights wiper etc)
Cant think of anymore at the moment - but i am sure there are other things to try.
But try resetting the ecu before doing all that. Every time you change something in the engine it helps if you reset the ecu afterwards.

Probably a stupid question. Just disconnect positive battery cable for abou t 10 sec. to reset?

Online Manual page F1-097 has a procedure - i think just step 1 is sufficient to reset the ecu

I used the great write up by Tunes on cleaning the tb and it took care of my idle problems. I recommend using it. Should be in the FAQs.

upgrade ur altenater to a 90amp vs the 60 amp it has. where form a v6 MX-3 or MX-6 both will bolt up to ur 1.6. u maywant to swap out alt. pulley i didn't but it stop the shity idel.

Limegreen mx-3 wrote:upgrade ur altenater to a 90amp vs the 60 amp it has. where form a v6 MX-3 or MX-6 both will bolt up to ur 1.6. u maywant to swap out alt. pulley i didn't but it stop the shity idel.

did this also prevent the lights from dimming when you hit the brakes?

if so i'll probably do the upgrade this summer.

Yes