Idling High when stop - PeachParts Mercedes-Benz Forum

#1 03-25-2003, 08:19 PM

I've just bought a W123 230E, two months ago.
A few things keep me wondering :-
(1) Everytime I stop, change the gear (auto) to parking(P), the idle will become very high.....until I press the accelaretor.....
(2) The ex-user installed the air-horn, so I have one selector switch to allow me choose either one.The air-horn work intermitently but the default/original horn is working perfectly.
What could it be ???
(3) Its difficult to start when the engine is warm during hot weather.I've to keep on pressing the starter until it start., and when it start..it will slowly (take few second) to take into the normal idling, as well as the fuel pressure meter..
But when the engine is warm, in cold/night time, it's easy to start (same as early morning).
Could it be the fuel pump/relay/fuel-filter/coil ??
Is it possible to test to change the fuel filter (cheaper) only without changing the fuel pump relay ??

Thanks for your kindest help ..

Kareem.

haasman · #2 03-26-2003, 01:36 AM

Kareem

Welcome to the forum ...

Regarding your questions:

(1) Sounds like you should check your throttle linkage for smooth movement AND lubricate it. It is recommended to use ATF fluid for the pivots and ball joints

(2) Strange, I agree. It sounds like there is a a broken or weak contact in the wire between where the new horn wire and the original horn contact wire meet. Check there first.

(3) Often starting problems are related to cap and rotors. Is yours a fuel injected model or carb? If carb, after checking the rotor/cap and plugs, I would make sure the auto choke is working properly. Best done absolutely cold (first thing in morning) with the air cleaner off so you can see the choke flap postion inside the carb throat.

You do not have to change the relay when you change the fuel filter. Often a "crush" washer is used to attach the lines. Be sure to install a new one if so used.

Hope this helps,

Keep us posted,

Haasman

#3 03-26-2003, 02:02 AM

Thanks Haasman for your reply !
Anyway as I'm consider a dumb to this engine part, appreciate if you could provide more detail or image if available for the items below :-
(1) Sounds like you should check your throttle linkage for smooth movement AND lubricate it. It is recommended to use ATF fluid for the pivots and ball joints
Answer - Where is the throttle ?
Is the ATF fluid same as the power-steering fluid ?
DO I need to spray them or how ?

(3) Often starting problems are related to cap and rotors. Is yours a fuel injected model or carb? If carb, after checking the rotor/cap and plugs, I would make sure the auto choke is working properly. Best done absolutely cold (first thing in morning) with the air cleaner off so you can see the choke flap postion inside the carb throat.
Answer - Mine one is injection, can I use the same method as above ?

You do not have to change the relay when you change the fuel filter. Often a "crush" washer is used to attach the lines. Be sure to install a new one if so used.
Answer-What is the best timing to change the fuel-filter ?
is it same as the fuel-pump relay ?

Sorry for the siily question but I'll try to learn quickly.
Thanks a lot for your kindest help.

Kareem.

haasman · #4 03-26-2003, 02:17 AM

Kareem

There are no dumb questions on this site! Ask as many as you would like.

(1) Answer - Where is the throttle ?
The throttle linkage is the gas pedal linkaage. When you push down with your foot on the gas pedal it moves the throttle linkage at the engine.

Is the ATF fluid same as the power-steering fluid ?
No, similiar but not the same. You could use other lubricants as well but Mercedes recommends ATF fluid (Automatic Transmission Fluid) any type will work.

DO I need to spray them or how ?
I would have someone move the gas pedal (while the engine is off) and you look at the engine and see what parts move. Take a long screw drive or other tool, dip into the can/bottle of ATF and then let it drip down on the pivots and linkages.

(3) Answer - Mine one is injection, can I use the same method as above ?
No, Fuel injection is different. You can not use the Carb/choke suggestion.

Often cold starting problems are related to the cap and rotor. Check these first and make sure they are good. Can you find Chevron's Techron fuel injector gas additive? If you can put two bottles in the fuel and drive around. You may have dirty fuel injectors and this would clean them. Sometimes takes a while.

Also, if your fuel injection system is working correctly, whether the engine is hot or cold, you should not have to use the gas pedal to start it.

Try these suggestions and keep us posted,

Haasman

#5 03-26-2003, 02:48 AM

Haasman;

Thas a kind of you to answer mine, promptly !
I'll try this after work, and let you know.
BTW, I've already changed the rotor and its cap when I purchased it due to wear&tare.

Thanks again.

Kareem.

#6 03-31-2003, 07:40 PM

Haasman;

My first problem solved.
When I tried to lubricate all the moving parts linkage to throttle, I found that the spring has torn-out, I change and it works !

I'm still don't have time to check the horn wiring as its to mess in the engine box, anyway I still can cope with the default one, so not a big problem for me.

Difficult to start, I'm sure what exactly the problem, I've put two bottles of fuel-injection cleaner and adjust the (vacum) by myself.
It seems improve as sometime it quite easy to start, but still sometimes it difficult (but not as previous).

Final one, what exactly could be made to reduce the harsh-shift-gear problem.My car always shift-gear harshly from 1-2 second gear, and from 4-3 (down-shift).

Thanks a lot for your kindest help.

Kareem.