Saturn SL1 running rough

Hope this doesn't get to long but here we go:

I have an 2002 Saturn SL1 that has been running rough lately. My check engine light has come on and when i hooked it up to a cheap reader it said "Cylinder 1 misfire" so i changed all the plugs and wires but that didn't help. It also idle's really high around 2000 rpm's in park and sometimes when i get off the highway i can tell it is a little harder to stop because the idle is not kicking down. Whenever i'm just cruising down the road from anywhere from 30-50 mph i can feel a little studder in the gas pedal but it will quit when i get on the highway or give it some gas. When i first start the car it jumps way up in rpm (close to 3000) then settle back down to around 1800-2000. I know that's somewhat normal but i have never had a car that jumped so high like this when i turn it on. I hope i have not made this to difficult to understand and i will try to answer any further questions to the best of my ability but i am no car mechanic. I am a DIY kind of guy and even though i don't know much about cars i seem to usually figure out how to fix them myself. So any information anyone can provide will be appreciated.

Milage?
how did the plugs that you took out look? (My buddy keeps foulin his out with identical problems)
Is it running rough all the time, or just idle?
The ECTS is reponsible for similar things as in so many other posts, but the '02 already has a good brass tipped one...
You can try cleaning out your Throttle Body with carb cleaner, wouldn't hurt, and could help.

Good Luck :)

I would agree w/ mysatilac that the throttle is a good place to start. Sounds like it might be sticking open or something. Is it possible a faulty throttle position sensor could cause this?

I haven't seen a Throttle Position Sensor go bad,
It's possible that the IAC inside the TB has become stuck open, which is similar to keeping the throttle body open

the throttle body is connected by three bolts (and your throttle cable, a vaccum line, and the two sensors wires) and is where the intake tube connects to. Be careful with the gasket when you remove the throttle body, also remove the IAC (idle air control) valve which is connected to the TB by two torx head screws, once it is out, spray the inside of the TB very well with carb cleaner while moving the throttle back and forth checking for binding and that it closes and opens all the way easily, then you want to spray down ithe IAC's pintle (the spring) and when satisfied that everything is clean and dry, reasemble and fire it back up. Hope this fixes your problem...

its the intake manifold gasket, it is common on the later SOHC to get sucked into the cylinder 1 runner, and some time the cylinder 2 runner as well. spraying some carb cleaner in this area will confrim the problem. if the gasket is leaking, the carb cleaner will cause the engine to bog down briefly.

hey guys thanks for all the help, i will try the cleaner this weekend when i jump into this problem. Thanks again for the quick replies and i'm sure i will be back before it's done. :)

as a second (safer) check for an intake/vaccum leak.

Use a piece of tubing, aquarium or other, as a stethescope. One side at your ear the other where you suspect a leak... And you will be able to hear a sucking/hissing sound. it is quite apparent and doesn't require you to bog down your engine.

I agree with sierrap that is probably your problem,

Check your vacuum lines also. Especially the one going to the brake booster. These guys are right on the money with the gasket leak tho. If you do use carb cleaner or brake kleen be sure not to light up right about then. Ahh, in my youth. :smokin: At least I was fast enough to get the extinguisher before before it was toast. Grease fires are a be atch. :2cents:

:lol: so true,:smokin: = http://www.emotipad.com/newemoticons/Flame.gif

:lol: so true,:smokin: = http://www.emotipad.com/newemoticons/Flame.gif

great way of puting it. LOL

actually i can hear a hissing sound without the tube. It's rather noticable at times just when i have the hood up. The spark plugs were black when i changed them but not like caked on and covered, i've seen worse. Someone I work with who used to be a mechanic mentioned the intake manifold gasket as well so i guess that's where i'll start. I've never really changed anything like this before so do you guys think i should take it somewhere or is it something that isn't that hard to change. I've always been able to figure out how to fix stuff on the cars but it usually takes me longer than what it should. Thanks again for all the replies, i posted on another website and never got any answers.


edit: i noticed i never put how many miles i had on it, it has 100,600. I drive an hour to work everyday and it really racks em up. :(

Someone I work with who used to be a mechanic mentioned the intake manifold gasket as well so i guess that's where i'll start. I've never really changed anything like this before so do you guys think i should take it somewhere or is it something that isn't that hard to change.
I think I might invite my co-worker (ex mechanic) over for a beer soon. :evillol: I'm not that familiar with the SOHC engine. The DOHC intake is a rather tight fit up against the fire wall. I think you should be able to unfasten yours and move it out enough to get a new gasket in.
Good Luck.

Originally Posted by mysatilac
:lol:so true, :smokin: =http://www.emotipad.com/newemoticons/Flame.gif
As Miss Hilton would say "That's Hot"