I just joined this forum, because I have searched high and far to solve my problem. I just bought a 1999 SL1 SOHC with 90,000 miles on it. Now, I'm fairly mechanically inclined and bought this car on a whim as I needed a commuter. When, I first bought it, it had a high idle of about 1,500 RPM. Whenever I went to shift (Manual) it would climb to about 2,000 RPM when I pressed in the clutch. After doing a quick google search it said to clean the TB and it would fix that issue. Since, I paid very little for it (from a friend) I didn't think anything about it.

However, last night I took the TB off and cleaned it real good and put it back on. No dice. So, I went down to Schucks and bought a IACV and replaced that (not sure if I set the pintle correctly), but now all of a sudden the idle is up to 3,000 RPM at idle and will occasionally drop to 2,000 RPM. It has never idled where it should be, not even cycling the key, battery, and PCM B fuse, so I eliminated the TPS (but not too sure).

When I cover the TB inlet with my hand, it seem's to better the idle, but I can't see in the car. But, still not where it should be. So, then I thought, ahhh must be a vacuum leak. No dice, I checked up and down, left and right with propane, starting fluid, and carb cleaner (02 sensor safe).

I took the EGR off and cleaned it and put it back on, no change.

I took the connector for the ECTS and it looked fine.

I'm just running out of ideas, however it seems like a common problem. I'm wondering if I should just replace the IMG?? What do you guys think? Any Help?

Thanks in advance!
Mike

 

Put the stock IAC back on. I had the same issue with my car at about the same mileage, but I got stuck in a parking lot long enough to turn on the service engine soon light and got the code P0509. I put on a new IAC and it did the same thing so I took it back.

I came to this web site and did a little search and found out about the intake manifold gasket problem. It gets sucked in on the top outer corner of the #1 port. Spray something like carb cleaner or wd40 around this area and if the idle changes, this is the issue. Use an aftermarket gasket like a felpro, do not use a GM gasket, they are too flexible, thats why it got sucked in in the first place.

 

Keith, I appreciate the quick reply.
I'll definitely do that since it was a pretty penny. I forgot to mention that I got that p0509 and p0404 codes. I don't know if those are right it was an IACV and a EGR code. I did try the #1 cylinder with propane, I'll take some starting fluid to it.

Thanks,
Mike

 

I tried to find the link to the original thread for this -- it was in a "How to" forum -- but couldn't. I saved a copy of it a few years ago and still have it so I'll paste it here. It helped me solve my high idle issues on a 1995 SL1.
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Due to the numerous threads about high idle, I have made this to help those with the issue...

Saturns tend to have high idle issues. There are a variety of possibilities that cause it, and a variety of solutions depending on whether the engine is a SOHC or DOHC. Regardless of engine, there are a few possibilities that apply to both SOHC and DOHC.

ECT- is the most common cause to all issues if not replaced. So even if you do not have a high idle issue, replacing the ECT will help to avoid future problems. It is a relatively cheap repair, and can be picked up aftermarket. You will need Teflon tape to wrap the threads of an aftermarket ECT to avoid leaks.

Engine Coolant Temperature Sensor R&R Saturn S-series

ECT connector - The connector has a tendency to corrode. It is not necessary to replace it if it is fine, but if you see any green gunk in there, then it needs to go. You will have to get this from a dealer, or you can go to a junk yard and find a IAT sensor connector.

Engine Coolant Temperature Sensor Connector Replacement

Vacuum Leaks - Vacuum leaks will cause high idle and are relatively easy to diagnose and find. On a SOHC around the years of 99-02 the intake manifold gasket is the most common issue for high idle. To find a vacuum leak you simply take water or brake cleen and spray around the intake manifold gasket to the head, the gasket for the Throttle body and all vacuum lines. Do this with the engine running. Should the idle change at all, you have just found the leak. An IM leak is probably not the likely cause of a DOHC high idle.

Carbon Build Up - This causes the IAC (Idle Air Control) valve to stick and gunks up the Throttle Body. If you turn on the car and turn it back off, then turn it back on and the high idle is gone. Replace the TPS with a dealer replacement and clean the connector. To clean the throttle body and IAC, follow RichPin's TB cleaning videos. This should be done on both motors regardless of the solution. This may also increase MPG.

Throttle Body Cleaning (part 1)of 3

Throttle Body Cleaning (part 2)of 3

Throttle Body Cleaning (part 3)of 3

Thermostat- If the ECT has been replaced and the high idle continues and the other common symptoms have been checked, check your temperature. For 1991-1995 your temperature should be around the half way mark. For 1996 up your gauge should read a needle's worth over the 3/8ths mark.

Saturn S-series Thermostat R&R

EGR valve- Try to clean the EGR valve if still no success then replace it.

.................................................. .............................

The order of sequence in which I would do these for a DOHC; ECT and ECT connector, Throttle Body Cleaning and IAC valve, Thermostat, EGR valve, then Vacuum Leaks.

For SOHC; ECT and ECT connector, Vacuum Leaks, Throttle Body and IAC cleaning, EGR valve, then Thermostat.

 

Might just be my 'puter, but none of the videos (other than the first one) will run ... "video does not exist" ... is the message

 

No, not your computer. I said that I had saved the thread from a couple years ago and it looks like all but the first one have been moved since then. If I remember correctly they are all from the "richpin" series. I'll remove the links but the rest of it should still be applicable.

Thanks for checking them out -- as I should have done myself before posting.

This is where I found all of the how-tos: http://www.saturnfans.com/forums/forumdisplay.php?f=26

I think all of Rich's how-to videos can be found here: http://www.youtube.com/playlist?list=PLDC13E2D20209FD3A

 

Stop in the new member area and give yourself a proper introduction, from there go to the USER CP top left and add your first name, location, and car to your "signature".