Fatherofthree

1994 Mercedes c280 w202 idle goes up and down in park, stalls when press accelerator hard from a stop, hear air sucking noise from throttle body, vacuum lines and maf seem good, coils and plugs seem good, could it be purge valve?

Plutoe

Faulty throttle body---find someone who knows the engine and has the diagnostics-else sell the car!!

Fatherofthree

Can you explain further because I do not want to sell the car. The throttle body seems to work well. When I punch the accelerator it make the noise of sucking in air. If that is for sure the problem, can you advise how to replace the part?

Plutoe

To do what you ask requires some engine diagnostic knowledge and tools.

What you are asking is similar to asking an electrician--"How to wire my house"---I am sorry you have to do your own research on your engine and I would suggest studying the throttle body circuit.(function,diagnostics and wiring)

Fatherofthree

I would appreciate it if you would not even answer any questions. Your attitude is arrogant and not helpful.

mbsickness

I would concur that the throttle body is your likely culprit. The throttle body is more than the throttle plate and body as there are a collection of wires that feed information to the ECU such as throttle position. As these wires use the same biodegradable wiring as the rest of the engine harness it will eventually fail. When this happens the wires short and the symptoms you are describing are possible. There could be other causes of your issues and this is where Plutoe's comments ring true. These parts are very expensive and just throwing parts at the car will not only be costly but can also not lead to a solution. In your case a scenario is that the wires in the throttle body are shorted and the ECU is cutting out the potentiometer signal and is going only on the MAF sensor data. When you open the throttle rapidly there is not enough fuel to stop the engine from stumbling as you have just flooded the engine with air and no extra fuel. This is just my guess but my car did have the same symptoms when the throttle body went bad. Hate to tell you but a new throttle body is about $1600.

Fatherofthree

Thanks so much for your detailed explanation. What are your thoughts on purchasing a used throttle body on line? Found a couple for around $200. My car is a 1994 with over 200,000 and afraid a new part is worth more than my car.

mbsickness

I would be very cautious with a used part unless you know if was either rewired or recently manufactured (replacement part). The wire issue will likely be present in most used parts. What is the part number on the throttle body? Should be on a green VDO tag. I might have a spare that while not perfect is still serviceable.

Fatherofthree

I called a dealership, gave them my vin, and they gave me the Mercedes part #0001415725. Would that be the number you need to see if you have a compatible part?

mbsickness

Good news and bad news. That is the same part number of the part I have but in the past three years sitting in the garage the wiring has completely degraded. I found the number of the place I had rebuild my throttle body and they charge $250 or so and it looks factory when you get it back. I'm more than happy to send you the part for the cost of shipping but it might be best to have your rebuilt. Here is a link to their ebay "auction"


http://www.ebay.com/itm/MERCEDES-THR...TaMDt-CIvxSUEg

mickey13

he comes off rough but knows his stuff. i guess as long as he is somewhat helpful he presents value and he did tell you what it was. take it for what its worth. otherwise, i think its a great community so...

i probably would agree that a computer diagnostic is needed except that sometimes even a mb star computer diagnostic doesn't get you much further than you are now.