Sorry to post here but thought a 3800 is a 3800.. I have a 95 lumina 3800.
Lately it stutters while driving like a missfire...gotten worse lately..
THEN today start it up and it idles like new for 1 min ...then idles up and
down like an idiot from 200rpm to 1300 for about 10 seconds and idles out
fine then starts back up in the idles surges.. What would cause this.. I
replaced all the plugs, fuel filter, air filter oil etc as it was required.
I tried the paper clip scan but this stupid thing has the weird OBD I scan
plug that can't be doen with typical OBD I gm scanners ($19 at parts store)
so I can't scan it to see what it's problem is. Thanx for your time

"Chevrolet" <whazzzupppp (AT) cogeblow (DOT) ca> wrote

can of throttle body cleaner. Take the IAC (Idle air control) valve. Spray
the heck out of the passageways on the throttle body. Spray the valve where
it meets up with the throttle body. Remove the duct work leading to the
throttle plate. Worke th throttle, spraying the area that the air flows. Put
it all back together. Do not sart yet.

Remove the positve terminal from the battery. Leave it off for at least 5
minutes. Replace the terminal.

Start it, ENSURE all accessories are off and you DO NOT touch the the
throttle. Let it idle for at least 5 minutes. It may sound rough, it may
stall.... If it stalls, repeat battery, then repeat this line. Once it is at
a stable Idle it is fixed. If it doesnt idle properly still..

Take it to a liscenced mechanic.

Micheal

I'll try that.. thanx
"Micheal Artindale" <micheal.artindale (AT) shaw (DOT) ca> wrote

well.. had it scanned... O2 sensor. Seems to have made it better but number
4 cyl is not pulling like the rest adn it has a slight rough idle to it.. I
changed the coil pack and plug/wire but thinking she has seen better days
226k on it. Does run not bad though. just at idle in park it seems to
stutter a bit... fine under load. Thanx all who replied
"Chevrolet" <whazzzupppp (AT) cogeblow (DOT) ca> wrote