98TypeR#21

Sorry folks, but I can't find the actual thread that I got the solution in, but it's simple!

First - background - my 2001 (70k miles) has been stumbling (dropping down below about 600rpm or so) for a few seconds after I let off the gas and let it drop to idle. It almost stalls. Very annoying. It's worse in hot weather.

But the solution is simple! The problem is gunk in the throttle-body, and someone pointed to a product that works REALLY well. I used it last night, and it solved the problem.

The product is from a dodge dealer, called Mopar combustion chamber cleaner (I think that's it). You let the engine heat up, take the intake tube off the throttle-body, spray the whole can in while engine idles (stopping when needed to prevent engine from stalling), after can is empty stop the engine, let it sit for an hour or two, start it up letting it idle for 10 minutes or so, then drive aggressively for few miles to clean it out. (note that you'll have LOTS of smoke during this time, but that's appropriate).

It WORKED.

For some reason I can't find the particular thread with the details, because you can't search by content (only subject line apparently) and I can't remember what subject line was used in the thread I found.

Hope this helps for others!

LeopoldS2K

would it be a good idea to change the plugs and oil after doing this?

98TypeR#21

The threads I was reading didn't say anything about that.

I see no reason to change the oil however - the oil shouldn't be mixing with the intake mixture.

phillys2k

do u spray the whole can in the throttle body?? do u have pics>??

98TypeR#21

Yes you spray the WHOLE CAN in (it actually takes at least 5 minutes - there's a lot in there, and you have to stop for a few seconds every 10 seconds or so to let the engine recover from stuttering). During this time you'll have LOTS of smoke out the back! DON'T park in your garage or you won't be able to see!

No pics - there's not much to show.

Although one of the threads I found yesterday had pics of the throttle-body without the plastic intake connected.

I'll search a bit more and see if I can find the thread - sigh...

afwfjustin

Wow, thanks for the heads up. I was wondering why my MY00 was doing that. It stutters right after I brake to a stop and seems like it's going to cut off and then idles fine again after. I'm guessing this is a problem on late model s2ks right? I'll have to look into this stuff; how much was it? Did you find any increased power/throttle response after?

Wisconsin S2k

this exact thing was posted in another thread somewhere.


and if i remember correctly, there were some negatives brought up about doing this.

xviper

I think you are basically spraying in "carb cleaner", although I'm sure the modern day version is injector safe, etc. It dissolves the crud buildup in the intake tract and flushes it into the combustion chamber where it's burnt up. This product also has a tendency to lubricate things like valve seals and clean the tops of the valves as well.
As you are spraying it in, did you notice that the engine nearly dies and you had to stop or slow down once in a while so the engine could "catch up"? It was probably not a bad thing to clean out the intake, but it may very well be this "choking" of the engine is what forced it to learn how to deal with trying to pick up the idle and prevent it from going so low. This is the same thing that happens when the intake air temps get really hot like in the summer time. On most cars, if left alone, the car will eventually "learn" and deal with it. You just made it learn faster and cleaned out the top end while at it.

marknconnie

there is some thing called seafoam that does the same thing. i used it on my old car. 93 integra gsr. and it work too

98TypeR#21

Good thinking about the ECU learning possibly contributing. But my ECU is reset everytime I start the car (I leave the ECU fuse out). So any learning is totally forgotten everytime I start the car.

So good theory, but in my case (and others apparently) this stuff really does work. I'm surprised that a small amount of varnish (or whatever) would cause this problem, but it definitely did!