When I start my car in the morning/afternoon, after it has been sitting overnight, and let it idle, the rpms will drop very low and pick back up. It will fluctuate like this until I rev the engine, and it will go away. A couple days ago, I started the car using the remote start in the morning, and it actually died out at least once. The strange thing is that it will only happen after sitting overnight. After it was running for a while, and shut off for the day, 5 or 6 hours later, it will start and run fine. I'm not really sure if I have a vac leak or a bad sensor, or something worse. I looked over some of the vac lines to see if i could find any cracks or rot, but I couldn't find anything. That'* not to say I wasn't looking at the right lines.

I would start off looking for a vacuum leak with a can of throttle body/carb cleaner. Spraying any small tubes etc that look like vacuum. In the picture it looks like you have a Century with the 3.1L. On top of the throttle body etc are a couple points that I always wonder..how don't they leak.

After that, if you still have an issue. Aim to clean the throttle body. The IAC is your car'* own way to control idle, aka metered vacuum leak. Make sure it'* clean and that should help it work better if it'* not holding up it'* job.

Bad fuel pressure regulator??? Easy to check.

I'm with Bill, check the IAC and clean the throttle body. From your description it only happens when cold, this leads me away from the FPR, but still worth a look. Do you have a SES light?

I tried using a can of carb cleaner, but the nozzle was screwed up, so it sprayed everywhere but where I wanted it to. I'll try to get another can and try again.

It is the 3.1, sorry for not clarifying that in my original post.

I'll take a loot at the TB after I check the vac lines again.

I agree with Dan, I don't think its the fpr as it only happens when its cold. It runs perfect any other time..

The SES is on.. But I don't have a code reader, and the cheapest that the local shops charge is around $50, not including "labor". The light has been on since I got the car, but I didn't think anything of it because apparently its a common occurrence in the Centuries, and I never had any problems with the car.


Thanks for the input guys, I really appreciate it.

Go to your local autozone, advance auto, what ever, they should be able to read it for free. Otherwise, you can pick up a cheep code reader for about $50 and read it yourself. Knowing that code will help us point you in the correct direction.

No Advance, or Auto Zone here..and the places that are don't have that program. I also haven't seen anywhere that has readers for that cheap. The lowest I have seen them for was about $80 on sale. I live in the middle of nowhere, so my options are very limited. I'll take a look around tomorrow to see if I can find a cheap reader, or a shop that will do it for cheap.

I just looked on Ebay, http://shop.ebay.com/i.html?_from=R4...All-Categories You can also try your local craigslist, might get lucky. Another option is if you have a smart phone. Android has a app called torque. You can pick up an adapter on Ebay, http://shop.ebay.com/i.html?_nkw=obd....c0.m270.l1313 The China ones are a bit slow and sometimes don't work.

Well, I'm SOL. Nothing on CL, Kijiji, or any other local classified site, and I don't have a smartphone. Your first ebay link didn't work. Are the ones that plug directly into the computer any good? Or this one: http://cgi.ebay.ca/Car-Scanner-OBD2-OBD-2-Check-Engine-Light-Code-Reader-/230643183118?pt=Motors_Automotive_Tools&hash=item3 5b367ae0e ? I don't have a lot of money to spend on this right now..

I've never seen that one, but it looks like about as basic a reader you will ever find and will give you codes and allow you to clear them.

On Ebay I just typed in OBD2 code reader,