**HELP** 93 SC2 Idling at 3,000 rpms

Hi everyone, I am new to the saturn world, I got a 93 saturn sc2 automatic 2 weeks ago, the car had an issue with idling when I got it, every so often the car would idle itself up to around 3,000 rpm's, then drop back down. I changed the throttle position sensor 2 days ago to try and remedy this, only to have the check engine light start coming on, the car would stall when I came to a stop, it wouldnt shift right because the rpms kept jumping up and down, so I changed the air flow sensor as well. Now the car runs fine, the check engine light is not on, etc. But now I have a new issue. If you start the car and its cold, it will idle normal at around 1,000 rpm, when you drive the car, if you let off the gas between 2,000 and 2,500 rpm the car will continue to accelerate by itself until it shifts, also after you drive the car and it warms up, when you put it in park the rpms climb to near 3,000. You can turn the car off, and back on, and it will climb right back up to 2,500 - 3,000. You can try to put it in neutral, and it does the same thing, and it will sit there, it wont go back down, it will stay between 2 and 3,000 rpms... but in drive/reverse the car sits at 1,000 rpms. I am running out of ideas on what it could be lol... Any help would be greatly appreciated as I want to try and fix this before it takes my tranny with it from shifting into gear at such high rpms. I have also changed the spark plugs/wires/air filter, and cleaned the pcv valve.
Thanks!
Rob

Sounds like it could be the ECTS. Engine coolant temperature sensor. This is a common problem with these cars. Go to the dealer to get a sensor that works properly. Probably should change the connetor, as well. Corrosion in the connector can cause a new sensor to send bad info to that computer. If yours has a short in it, the engine idle and other driveability issues will be present.

You stated you have a check engine light. Your 1993 car has a OBD I diagnostic. Take a paper clip to the A/B on the connector located to the left and down from your steering wheel. It will flash 1 and then 2 and then flash all other codes before closing out with the 1-2 code. Get those code #s and post them here. Next, your high idle is likely related to IACV located right next to the TPS. You are better off to remove the entire throttle body and clean it out good. Remove the electrical connectors, the accelerator cable and vacuum hoses. The throttle body comes off with the 3 10mm bolts as looking into the unit after taking the air intake assembly. The gasket sandwiched between are generally reusable however they are not costly to replace from a auto parts store. Be careful around the IACV when you remove it since it is a servo-motor with a spring. It has an o-ring also. A can of carb cleaner and some old toothbrushes are recommended. Do not soak the tps or iacv. Just apply and wipe off.

You will see why the high idle when you see the throttle butterfly from the other end.

Alright... I changed the coolant temperature sensor, still no difference, the check engine light isnt on, it was on when I changed the TPS, and went off when I put the new air flow sensor in, I sprayed carb cleaner in the throttle body and scrubbed it with a paper towel, theres no resistance in the butterfly, there was a little before I cleaned it, and now it moves freely, once again, the car only has the idling issue when its warm, if the cars parked for a few hours / overnight, the first time you start it it idles fine, and it runs fine, once it warms up it starts idling high when you put it in neutral/park, when you put it in drive/reverse it idles at 800 rpm, and it continues to accelerate when the rpms are between 2,000 and 2,500 rpm while your driving if you let off the gas, so... So far the checklist of things that have been done is:
TPS Changed, new one was tested to ensure it wasnt faulty,
Air flow sensor changed, tested to ensure it wasnt faulty,
Coolant temperature sensor changed,
Plugs changed,
Wires changed,
PCV Valve changed,
Air filter changed,
Throttle body opening cleaned and butterfly moves freely....

This is why I am getting so frustrated, I cant figure it out, and so far it hasnt been anything obvious.... Any more suggestions? I will try anything at this point lol...
Rob

look for a vaccum leak or a stuck IAC(idle air control valve)

Sorry, the idle air control valve is the one I just changed 2 days ago with the TPS, it is the one mounted right below the TPS, so thats brand new... I checked all the vaccum lines and cant find any leaks / cracks / etc... The car ran and idled fine until I changed the TPS, I got the car about 2 weeks ago, every now and then it would idle up to around 3,000 rpm when it was in park, so I changed the TPS, then it started sputtering/stalling/ and popping the check engine light, so I changed the idle air control valve, all of that stopped, it was good for about a day, then it started with the fast idle when it was warm, I changed the coolant temp sensor today, and still no avail... If you could tell me how to read the code on the computer, I can check and see if it has a code saved, and also clear it, maybe it bypassed something in the computer when it had the issues before I changed the air control valve...? Thats the only thing I can think of...
Rob

I checked the codes on the cars computer last night and it didnt have any stored...

High idle will be related to a vacuum leak or those parts you have installed. Ensure that the IACV o - ring is present and all is seated properly. There are instances where it is not the IACV or TPS but the quality of the connector. Follow the vacuum lines and spray carb cleaner about the throttle body area to see if there is a change. If the vacuum lines are original, maybe there is cracking at a turn facing the firewall.

I did that with the spray and there wasnt any visible leaks, the O-Ring is in place on the IACV, there is 2 questions I have, 1 is could it be the MAP Sensor? I took it off and there was buildup in the hole that goes into the manifold, the 2nd is there is a piece attached to the drivers side of the valve cover, it has 3 vaccum lines coming off of it, 1 goes to the throttle body and 1 goes to the egr valve, those 2 are there, but the 3rd is broken off and has been since i bought the car, and i cant figure out where the line would even go to
Rob

This is my answers to your questions:

( 1 ) http://www.saturnfans.com/forums/showthread.php?t=102885&highlight=MAP+sensor+idle

(2 ) I believe that it is like that from the factory..similiar to this from a SOHC

http://www.saturnfans.com/forums/attachment.php?attachmentid=8184&d=1173546332

Alright, well, I tried plugging the vaccum line to the egr valve, and still no luck.... Do you think it could be the MAP Sensor?

So I just changed the MAP sensor out with a new one, still no luck... Im wondering if autozone sold me a faulty idle air control valve... Thats the only thing I can think of, im really testing your saturn knowledge here, if anyone has any more ideas, let me know. lol.

Anything is possible regarding a new part being bad.

Just for a slight possibility... how old is the battery and have you had the charging/alterator system checked lately?

Saturn is one car that needs a good, clean supply of current to run services and especially that automatic transmission.

I dont know... I just got the car 2 weeks ago, its a never start battery... But I havent had any issues with the lights dimming, battery dying / etc... I also took the throttle body off today and cleaned it, no luck on that either... lol, when I took the IACV out to clean the throttle body, it was all the way in the extended position... If that means anything...

That high rpm indicates a very high vacuum loss. Are you sure all the vacuum connections are solid like the one connected to the brake booster on the firewall and pcv. I would start taking some of those main vacuum connections off and plugging with a golf tee or a pencil eraser as applicable to see if you get any variation. I would think a faulty TPS or IACV would give you a 2k high idle but 3k is uncontrolled. Again, no codes?

The IACV is a servo motor getting signal from the PCM to operate as such. It will stay in the last position as commanded by the PCM. I would tend to believe it is operating correctly based on the condition you report.

The spraying about the intake manifold when at high idle can indicate if a intake manifold gasket is at fault.

You are now at the point of beyond visual of vacuum hoses and its time to pull each completely, check and clean before reseating on both ends.

Not a single code... Of course, its my car, it couldnt be easy... lol
When you first start the car in the morning, it idles between 800 - 1000 rpm, when you drive the car to operating temperature, and put it in park or neutral, the idles sit anywhere from 2,500 - 3,000 rpm, but ONLY when the car is warm, not when you first start it. With it in drive, reverse, or any gear other then park and neutral, it idles at 800 rpm, it doesnt bog down when you hit the gas, even if you slam on it, it doesnt sputter, it doesnt stall, etc... I had the car running today when the idle was up, and sprayed an entire can of carb cleaner over every vaccum line in the vicinity of the throttle body, the pcv valve was replaced today along with the hose going from the manifold to the pcv valve, and new clamps where put on to ensure it was tight, the throttle body was cleaned, etc, it is all shiny, I tried plugging the vaccum line going to the egr valve, no change... Im so lost. lol. What should I concentrate on now... You mentioned a vaccum line on the firewall...? What about the knock sensor? or the PCM going bad? But I would think any of those would trip a code... A few times today when the car was turned off and back on, the idle remained at 1,000 rpm, even after driving it, but that was only like 3 times out of maybe 11 - 12 of it being started today.
Anyone in NH wanna buy a 93 Saturn SC2 with 18" rims and 215/35/18 tires? rofl

I didn't take the time to read all the prior advice posts. But I can tell you I had a 96 LeSabre that I couldn't keep under 60mph without the brakes.

It was a bad computer chip/brain which was a $750.00 fix.

Good luck!:2cents:

This SC is a charm all right.

The large vacuum hose coming off the brake booster going to the intake manifold is on the firewall in front of the driver's position. Check that out good. Its round and black with a hose in the middle of it. Check that connection and follow it all the way to its other connection. Check the entire length for fraying or cracking.

Have you taken the EGR off and clean it from underneath ensuring the pintle runs well. Carb cleaner, a toothbrush and dental tools. DO that and before putting it back on, start the car so it will blow any build up inside out. Make it brief and it will be loud.

I havent tried cleaning the egr valve, I tried taking the vaccum line to it off and plugging it, and it didnt make any difference... I will try taking the egr valve off and cleaning it today, and I will look into that vaccum line and let you guys know

So I tested all of the connectors, the one going to the coolant temp sensor, TPS, IACV, and MAP Sensor, all are right on per the specs in haynes manual... I called the saturn dealership and all the guy could say was 'The three most likely causes are a bad connector to the CTS, bad egr valve, or a leak in the intake manifold gasket.... *Sighs*

I have a 2000 saturn sl1 5 speed sometimes i push the clutch in when im at a red light the car revs up to 3000 rpm's. sometimes when i shuts it off it will go back to normal sometimes it don't sometimes I have to do it several times before it goes back to normal. While the car is idleing the car bucks and it is not easy on gas for a 1.9 motor. I've brought it to a small garage he told me it could be the idling sensor and he said there are two of them there could this be it?
Thanks
Cory

http://youtube.com/watch?v=4ilHTkyWRpU


Those devices connected to the throttle body are likely what the mechanic is talking about however one is the throttle position sensor and the other is the idle air control valve.

I have a 2001 sl1 saturn that when I bought it was doing the same thing and It was an Intake Manifold Gasket. To check spray some carb cleaner right where the intake mounts to the engine, If the idle drops replace the gasket. I replaced mine and the idle dropped to about 1300rpm that still wasnt low enough so I checked the idle control sensor that is supposed to drop the idle when the car warmes up it was cracked so replaced it with a new one and the car runs perfect. The old one looked like it was made of plastic the new one was brass. Let me know what happens.:rolleyes: