my car also has bouncy idle don't really know how to describe other than, when at a stop light car warms up and engine starts like bumping a little here and their different pattern every 1-2 seconds. car doesn't do it's bouncing when driving or on highway only when warming up to regular temp. in the morning when warming up it's fine.

Replaced/done: fuel filter, oil filter, oil change, wires, plugs (distrib) looked good. ran 2 bottles techron threw (helped a little). RPM/oil pressure stays to norm, doesn't move up or down.
Check engine light does not turn on until 2 days ago, i got my mechanic to pull code/reset code 22? don't know what that calls for.

Cars adding a few more cranks for engine to turn on, doesn't seem like anything too pressing, but is it?

Any suggestions on what to check or do next would be great, I'm stumped - thanks!

I had an intermittent bouncy idle when warm, and found that not all of the various throttle linkage bits were returning to their proper idle state. Some of those little nylon rollers were binding, and one of the "hey, I'm in idle!" micro-switches was not being activated.

It was intermittent because if the pedal was let back with enough momentum in its favor, the linkage would return to the stops. If it was let down easy, it would stick.

Cleaned and lubed every moving part on the linkages, and the problem cleared up. I used white lithium spray grease. Others prefer ATF for this.

If you are lucky, this low cost/low tech 'black box' approach will work for you too!

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1986 300E 5-Speed 240k mi.

I had the same problem and found the same solution. Check that the microswitch and Throttle Postion Sensor both provide the idle signal. (TPS has three leads - idle, WOT, and ground. It can be tested at the connector in the harness channel above the inlet manifold.) My TPS only showed an intermittant idle signal when exercising the linkage, so I partially disassembled the linkage, including the socket joints links down low, cleaned, lubricated, and adjusted. Used white lithium grease on the socket joints under the inlet manifold and WD-40 on the roller joints above the manifold. End of problem. Took about an hour.

Duke

thanks guys for your input!

i'm kinda understanding what to do now, but i don't know how to even begin looking where the parts/microswitch are that i have to grease/clean. I am trying to save some money here, cause i don't have extra $$$$$ to keep throwing into my car.

i think it's weird, cause my mechanic said for my type car with my mileage 178K, said it was normal. I never believed that, or feel that's a good enough answer. So any diagrams or links to websites or whatever (books to buy?) would be most helpful! i really, really, appreciate the help. I am just a beginner but hope one day to understand this better.

thanks!!

Just take off the air cleaner. The microswitch is on the linkage, and the TPS is at the end of the throttle valve shaft under the airflow meter. Follow the TPS pigtail up to the connector in the harness channel along the top of the manifold, disconnect it and figure out which of the leads is ground, WOT, and idle, then run continuity checks to ensure that the TPS is giving the idle and WOT signals. The microswitch function is obvious, It's either on or off and should be different at idle than when the throttle is opened a little bit.

I have no idea of your level of mechanical aptitude or experience, but if you've ever used a multimeter to run continutity checks and small tools to do minor disassembly and assembly like fixing a small appliance you can do this job without a manual or pictures. It's pretty obvious when you take off the air cleaner and look at the linkage.

Duke

thanks guys for the input, i'll try to get to it sometime this weekend, and i'll check back with ya! thanks.