[peponchas]

Hi everyone, I have a 1992 190e 2.3 8v.
I been having a very difficult time starting the car in the mornings, it takes around 10 to 20 tries to get the car going. Once the engine is on and warmed up to 80C-90C I'll have no problems except when I come to a long stop light, the engine starts to rev low and then high, like in a oscillating fashion, if I don't get my foot off the brake or accelerate, the engine will die. I can start the car almost immediately after that.
So far I replaced all the breather hoses with new ones, cleaned the Idle Control Valve, new K&N air filter, new coolant temperature switch.
I ran the car without the OVP relay for a few days and the oscillating revs and stalling were gone, same cold start issues.
I replaced the OVP relay with a new one, oscillating revs are back and cold start issues are present.
The engine and transmission was recently rebuilt.

 

[peponchas]

Also I was taking a look at the vacuum hoses and noticed that some are unplugged. Correctly reattached some of them following the diagram on my car but couldn't figure out the ones coming from the thermo valves (19.03, 19.13) that go to the throttle valve housing (3.03)

Please Help!

 

[dfresh22]

my engine use to rev low and than high (its pretty embarrassing at a light).

it was the intake air hose. maybe yours is not properely fitted on there?? i would double check all the fittings and make sure that their are hose clamps on each one of them.
as for the vacuum hose, the connection on the throttle valve housing is at the back and kinda discrete. just search all forums for "throttle valve housing" and there will be one with a diagram

 

[peponchas]

Thanks dfresh22, will look for loose breather hoses.

 

[Jippi]

when was the last tune up?

 

[peponchas]

Found and attached all the vacuum lines/plugs. Car is running better and start is a little easier.

@Jippi: Engine was rebuilt in June 2011
New pistons, rings, cylinder sleeves and valves checked and calibrated.

The problem I have now is that the mix smells too rich.

 

[Jippi]

when was the injectors last changed? i assumed that when you did the rebuilt you used new plugs wires, cap and rotor, fuel filter etc? when you did the plugs did u use oem plugs or at least non resistored, no plat plugs? tune up means

 

[peponchas]

Jippi:
We used new plugs wires, cap, rotor and spark plugs. I don't remember what type of spark plugs they are. But will check tomorrow.
What type of spark plugs you recommend?
Injectors where not replaced. Fuel filter was replaced a weeks after engine was done.

 

[Jippi]

i would use oem. mercedes has a stock of h8dco in their oem mb parts boxes.

 

[peponchas]

Great, thanks for the info. Will check the spark plugs and post tomorrow.

 

[peponchas]

FOUND THE CULPRIT OF THE PROBLEM

Hi everyone, it was my coolant sensor plug that had a short and it was making the car hard to start.
Will repair the plug this weekend.
Thanks.