Was wondering if anyone could help me diagnose this problem, although I may already know what it is.

My MY04 with 16,000 miles has been almost stalling when I come to a stop. It is a very subtle drop in rpm's, but, it does cause the car to shake/shudder. It is not consistent. I changed the oil 3,000 miles ago with Mobil 1 and the levels are good.

Any thoughts yet?

Now, several months ago, Conoco-Phillips (Standard 76) in the Seattle area had mentioned that their gas was contaminated with a polymer and it was gumming up fuel injectors. Well, I pretty much only fill with 76 gas. So, I am thinking my injectors may be clogged. Would this be a reason for near stalls? If this is possible, is there an additive I can try to clean the injectors? If not, I guess the next step is to bring it back to the dealer for warranty work. Problem is, I know the car wont act up when the mechanic drives it.

thanks for your input !!!!

 

Another member was telling me about a similar problem....he replaced his MAP sensor and that solved the problem.....

 

Tap your MAP sensor with the handle of a screwdriver to knock out any particles and see if that helps.

 

have the same problem with my 00 sometimes.. what is a MAP sensor and where is it?

 

If you look at the end of the intake tube, right where it enters the intake manifold, you'll see a small black box with a harness coming out of it.. it is screwed down and has the word MAP on it. A gentle tap with screwdriver usually does the trick. I just got a CEL a little while ago, and this trick worked to get rid of it.

As for what a MAP sensor is, its a sensor that reads the intake air charge. Not sure if it reads just the temp, or the density (same thing really). But I believe it adjusts the air/fuel ratio based on its reading. If it gets crappy readings (dirt), you'll sometimes shuddering issues while idling.

Someone please correct me if Im wrong!

-Chris

 

^ Sounds like some good advice.

 

I have the same problem with my MY01 with 9K miles on it. I tapped the MAP sensor and reseated the connector and so far it is ok.

 

"MAP Whack": http://forums.s2ki.com/forums/index.php?showtopic=209708

Your ECU could also be having a momentary brain fart due to a recent climatic change in air temp, air pressure, humidity, etc. in your area. Give it a few episodes to try to "learn" WITHOUT using the gas to "help" it stabilize the idle.
An ECU reset (BACK UP fuse pulled for 30 seconds) usually goes well with the MAP whack.

 

Thanks for the awesome input. I will give the Map tap and whack a shot. Also, very interesting about climate changes and the ECU learning what to do. The weather in Seattle has changed significantly this weekend (Sun and heat!).

Funny, I believe you guys, but if the dealer told me that the ECU had to learn what to do I would have thought he was blowing me off! javascript:emoticon('')

 

will try the "MAP tap" !

I'll let everyone know how it works.