My 1997 E200 (gasoline) has develped a curious fault.

When on the open road the car drives well but does not like to take hard throttle. However when slowed down to a crawl such as at traffic lights and junctions the engine doesn't like to take the throttle at all and it needs a lot of feathering of the accelator pedal to get the revs up to level that the engine is running reasonably evenly.

The problem is 10 times worse when the car is going up a hill and when there are passengers in the car. The engine splutters and misfires and sounds like it is (almost) running on 3 cylinders.

I thought is was dirty fuel and drained the fuel tank and changed the fuel filter - this did not cure the problem.

It was then suggested to me that it was the Mass Air Flow Sensor that was faulty - I changed this too but again the problem persists.

Has anyone-else experienced this problem and what was needed to cure it?

All advice warmly welcomed

Thanks

 

whats your fuel pump pressure and fuel pump volume should be around 1 liter in 60 sec. and psi should be at least 45 or higher. als ois your car misfiring under load if so repair these peoblems possible plugs and wire or fuel pump

 

did you manage to find out the problem.if u did wot woz up with it!!thanks

 

Hi, Im new to this forum. My car having exactly the same problem. My mechanic change the coil but the problem still exist. He thought the problem caused by ECU but I doubt about it. Dont know what to do now. May be you found the solution for your car. Any advice is appreciated. Thanks

 

I was away working in Africa for a charity so only recently returned and have got around to trying to fix the problem.

I changed the fuel pump and plugs this helped slightly but the problem is still there.

I spoke with a friendly local mechanic only yesterday and he raised the the same issues that Vytamenc did - check the plugs and plug leads.
I told him that the plugs were replaced but he said that not all spark plugs are the same.

He said, speaking from personal experience, that German cars need German spark plugs i.e. Bosch and he said only Bosch would work properly.
I have yet to do this.

On the plug lead issue, the mechanic also told me to do the "midnight blue" test which means removing the topmost aluminium cover over the spark plugs (simple hex bolts) and with air pipes etc back in place (but not the cover) then when it is dark (hence midnight) leave the bonnet open start the car and then look at the plug leads carefully - any faulty plug lead will show itself up with a slight bluish glow.

He did say however that with the car misbehaving going uphill then the leads may need to be carefully wiggled using a wooden or plastic non electrical conducting thin stick.

Any thin area of insulation which may have been abraded down over time will show up as a bluish glow and any break in the insulation will result in a visible spark.

His estimate is that changing the plugs and the leads will most likely cure the problem and if it doesn't then it is still a good thing to do as good plugs and a strong spark delivered through new leads will help improve performance generally and also fuel consumption.

I am going to try and get the Bosch plugs today and do the midnight blue test and will post what the result is.

On the ECU issue, I raised this with the local guy as being a possible problem and he said it was highly unlikely.

 

Thanks for the prompt reply. I already change the fuel pump, so the next step is to check the plugs. Hopefully this will solve the problem.

 

Hi Yee,

Well I would not have believed it if I had not done it myself... I took out the plugs and they did not look at all bad, however I decided to change them anyway and the problem is now solved.

As I say it is almost unbelievable that a plug problem was causing all the headaches. It just goes to show that it is always best to start in solving teh cheapest end of the problem first!

I did have a look at the BOSCH webiste to confirm the plugs specified for my vehicle and one thing that I noticed is that they recommend that the oxygen/lambda sensor is changed as a normal service part (max 60k miles) as it is this sensor that relays the info for the ECU to instruct to run rich or lean as the case may be. I will therefore change this and that should be everything absolutely 100%.

I hope everything works out OK for you too.

 

thats great, which part of africa where you in!!

anyways with my problem, my cars misfires too, but the rpm doesnt go passd 2500, sametimes when revving it too hard it switches off.some idiot in kenya told me to change to the complete trottlebody complete, it costd me alot. man!!!and that didnt change a thing,am stuck..changd the ecu, complete exhaust, not tird the o2 senors..

hope it wil work..
i need to go back to Europe...

 

Hi, my car still with mechanic. Call him just now ask him to replace the plugs, hopefully it also work for me.

Cheers.

 

Hi all, I change the spark plugs as suggested by esmerc. For the past 2 days no more misfiring, the engine run smoothly. I hope this will remain and does not cause headache anymore.