Erratic Idle... Help Please!!!

[Blaster2005]

I have a 93 Festiva. My problem is that just recently it started developing an erratic idle. The car has lots of power and runs great at high speed, but in town when coming to a stop sign it will sometimes start having an erratic idle. It's doing it more an more often, than before. It's a fuel injected car with a 5 speed tranny. The engine check light is off, but is in working order. Any ideas would be appreciated!!! Thanks, Mike & Abby

[mattswabb]

Start by checking the wires, plugs, cap and rotor.


matt

[oxbrain]

When I bought my car it had the same problem, it would idle really rough but run fine otherwise, got to the point where it was stalling out at every stop sign. Car had brand new plugs, wires, reman distributor, cap, coil, and battery. I turned up the idle a little bit and problem is solved. I don't know what the idle rpm is but it doesn't sound too high

[Biff]

I've heard that O2 sensors become weaker as time goes on , possibility?

[gomer]

o2 sensors can be tested off the car with a torch and a multimeter.. festy's use generic single wire sensors (about $20) ,, I don't have the voltage specs in front of me but the main thing is that it must create enough voltage and also (even more importantly) that the voltage changes quickly enough when o2 is added to the sensor (ie. removing the torch).. when o2 sensors fail they are rather predictable and not an on and off thing... this doesn't sound like an o2 sensor problem to me.. I have a 93 FI festy that is doing something similar and I believe it is the idle bump solenoid ,, I don't know what triggers it's function but I just bumped the static idle setting a bit...

[miami man]

idle

I had about the same problem last week. after putting new plugs and checking everthing else in the ignition system i started tracing the vacume hoses and found out that one was disconected from the plastic connection. after fixing that it ran well for a little bit but the idle problem came back. i disconected the positive battery cable for about 10 minutes to clear the computer and after reconecting it and drove it a little bit it runs like a top. i felt kind of dumb because i was looking for something major and all it was was a vacume hose that came loose