c180 w202 throttle problem

[Septic]

Hi Folks

got a revs problem with my c180 w202 1999 originally the problem was that when i started the car the revs would fly up to 30k rpm then drop below 5 and cut out
after the car had warmed up from driving the idle would be a bit over 10k
and the throttle peddle would be very sensative. I disconnected the wiring loom that comes from the throttle body thinking that it was a throttle position sensor (within the body) problem tried the car when driving its fine. So i replace the throttle body with a second hand one took the car for a drive
but still have the same problem. Ive no idea what to check next and its proving quite a challenge to drive the car when it want to idle a 10k and the slightest touch of the throttle pedle sends to car into warp.



Any help would be great.



Thanks Stephen

 

[television]

If your car has motronic, and I think that it does, the switch that changes over to the idle circuit may not be working, it is built into the throttle body /air flow as: and the end stops wear,stop the switch from closing,,it is possible to file away the linkage so that it will close.

What happens is that when it cannot switch to the idle circuit,the engine runs in the fail safe mode of about 1200 rpm

 

[Septic]

There is an adjustable rod that connects the throttle cable to the throttle body via a mechanism could i adjust this so that it doesn't touch the Button?



Thanks Stephen

 

[television]

The switch for the idle is inside the airflow plate body. The air flow plate works on a canter lever action that operates the switch, then the plate is closed, so should the switch be,,this can be checked with an ohmmeter from the plug on the side

 

[au.hanson]

Hi Folks

got a revs problem with my c180 w202 1999 originally the problem was that when i started the car the revs would fly up to 30k rpm then drop below 5 and cut out
after the car had warmed up from driving the idle would be a bit over 10k
and the throttle peddle would be very sensative. I disconnected the wiring loom that comes from the throttle body thinking that it was a throttle position sensor (within the body) problem tried the car when driving its fine. So i replace the throttle body with a second hand one took the car for a drive
but still have the same problem. Ive no idea what to check next and its proving quite a challenge to drive the car when it want to idle a 10k and the slightest touch of the throttle pedle sends to car into warp.



Any help would be great.



Thanks Stephen

This is a common issue with the actuator body(what you would call the throttle body). Uninstall it and clean it thoroughly in and out to clear all the carbon deposits due to fuel issues and reinstall it back. You may use carb cleaner or any other solvent to do this , you can even use fuel..

The second hand you bought is also dirty with some carbon deposit, so clean it up too.

You can minimise this in future by always buying unleaded fuel(fuel with additives to prevent carbon deposit in the combustion chamber) , or try as much as you can not to rev above 3000rpm to 4000rpm while driving to avoid this carbon from building up in excess, with this you can be running clean