2004 Chevy Cavalier 4 cylinder Engine Surge

this could be a lot of different things.going on here could be bad gas, clogged fuel injectors, fuel filter, fuel trim, bad pkugs and wires please tell more and what have you replaced

cold engine idle surge. (problem)
RPM range of surge not stated
300-700 or 800 to 1500? (range is critical to diagnosis)

bad fuel
running summer fuel in winter (running old fuel?)
needs a tune up bad, see the list in the operator guide.
idle speed controller,sticking or EGR valve same. (clean them)
location not stated, so cant guess about local air temps.?
no other symptoms, lack of engine power? etc?
was it ok last week, or better, when was the last time it was OK?
1week, 1year?
surge , causes, on a tuned engine might be:
1: too lean. so lean the ISC can not control idle. rpm low, stalling
2: too rich, flooding, stalling, spark plugs foul (look at them)
3: weak compression in 1 or more cylinders.
4: bad spark.
5: air leaks, in the plenum causing , ISC to lose control.
why high RPM?

especially?
well that means it fails hot too.
and there is a simple tests. for hot surge.
is engine fully hot? 180F and holds solid there?
say rpm is about 800
and you turn on head lights, heater fan and (not AC) and defrost.
the RPM must hold or the ISC is failing.
ISC -= idle speed controls. (all EFI has this function)

Check your vacuum lines for leaks. Symptoms suggest vacuum leak.

I'am not sure but sounds like an automatic choke problem

it sounds like its drawing air into the inlet mannifold

depending on what kind of car it is i would change the idle air control valve and clean throttle body if applicable

i have a 2001 chevy z-71 5.3L. I keep getting a random/multiple misfire code for cylinder 1 . I have replaced plugs, wires, coil pack(only on #1 cylinder)., and fuel pump. I still keep getting the cylinder 1 misfire code. I put truck on a scanner and watched the cylinders. # 1 misfires at idle but quickly stops misfiring at around 1000 rpms. you can here the engine miss at idle but truck runs great on road . anyone else ever had this problem?

I bought my 2004 aveo 49 miles. I've had several issues with the car. But recently I been experiencung high idle at start up and clutching. I change IAC. Plugs and wireds. Nothing worked. Today the high idle became constant. It was a metal bubble flex tube near the IAC unit that goes to the exhaust stuff down behind the motor. It apparently was cracked cause today it broke causing the constant high idle sound like a vacumn. We blocked it off with a stick to get the idle back down to 900 rpm instead of 3-4000 rpm took we can get to auto zone for high temp hose per Chevy dealer. I hope this helps someone cause it was fustrating and costly.

ignition mod. grounds,pcm or timing belt could all be it but, I would have to look at timing first.

Sounds like the dealer is shooting in the dark at your expense. If it was the O2 sensor, it would throw a code. Ofcourse, Fords drivability diagnostics was bad back then. I don't remember exactly how the ignition is set up on them. I would be looking at the trigger sensor for your ignition and ignition module.