93 Camaro 3.4l v6 with a rough idle, what kind of things should I check. New plugs and wires did not fix. Primarily happens when temperature is cold outside, temperature of motor doesn't seem to make any difference. Only happens when car is under load, dropping it into neutral or park and it smooths right out. Also smooths out if I bump the idle up even the slightest bit. When idling under load it is rough and the RPM's tend to fluctuate up and down slightly. Runs great aside from the rough idle, any ideas?

 

i have the same problem with my car im trying to hunt down

 

The idle air control valve IAC may be crudded up or/and throttle linkage sticking, dirty air filter, dirty throttle valve. Also check IAT Intake Air Temp sensor.

 

how would i check that sensor?

i am going to go grab a new air filter and a can of carb cleaner and go to town ....will using seafoam help at all u think?

 

do you have good fuel pressure? the IAC valve could be the prob..any vaccum leaks??

 

havent tested either yet

i just bout a new
fuel filter
air filter
pcv valve
plugs
wires
and seafoam

i will post if it fixes my issue

 

i cleaned the tb and the iat sensor also ran some seafoam in the vac lines and change the pcv and air filter....still no luck

the car does rev up a little smoother now

friday i will change the plugs,wires,fuel filter and post results

 

This issue is one of two issue I am having with my 3.4L currently. A lot of V6 owners seem to have this problem, it's quite common. Sometimes it's so bad at the light I just put it in neutral.

My revs also fluctuate. Another thing I noticed, is when the car is cold and I'm traveling at low speeds or idling in "Drive", the idle is very rough and low (400-500rpm). The car almost feels like it's going to shut off but doesn't. Then when I accelerate, it causes a slight hesitation that goes away as higher speeds come. I figure it could be a vacuum leak but I've looked through the engine with no luck.

 

ok so today ui just got done the following

cleaned the iac
put a new fuel filter...old one was original with 126k and black **** poured out of it
new plugs and wires...previous owner put bosch plat 4's and they were all black and not even hand tight

but it still idles rough when in gear i even sprayed the vac lines with carb cleaner with no luck finding a leak

car does drive smoother now and doesn't hesitate from a stop

 

Hello, I had the same problem you described with my 1996 3.8l camaro. Does your car throw any codes? My egr valve is what caused my car problems. Instead of me spending the 100 dollars and replacing. I just simply bypassed it. As soon as i started the car back up it was running smoothly haven't had any problems since. This has been about 4 months ago now. Let me know if this helps.