oh....my.....god!!!!!!!!!!!!

[mr. serious]

I posted the 'safe mode?' thread about 10 minutes ago and there is nothing!!! Is it me? Is it everything electrical I touch that turns to s**t? I must have some serious static going on around me...my PC crashed at the time of submitting the thread!!!

Please help me guys. Since the electric window problem was rectified with your help, the car is now in SAFE MODE, I believe.

It ran lumpy at idle when I started the electric window resetting the other night after reconnection of the battery, and then carried out the lock to lock procedure to get rid of the BAS and ABS faults. I let it run a little while longer as I know you have to let the ecu reset itself after battery disconnection, and the idle smoothed out and ran 'normally'. So I switched off and went back to work.

However, driving home this morning it ran terribly inasmuch as it would not rev over 4000 rpm, in neutral and in all gears-so at least the gearbox isn't locked out! Drove around for a while to see if it would clear itself but it hasn't.

Took off the MAF plug (Malcolm suggested in a similar thread) and made no difference. Also, just to note the car ran supremely well before the battery disconnection, so if something HAS gone coincidently t*ts up I would be extremely surprised.

Any info would be (as always) gratefully appreciated.

Ian

 

[jibcl500]

You need a new battery, get it tested!!!!!!!

jib

 

[television]

Do a running voltage check should be 13.8v or there abouts

 

[mr. serious]

New battery???? EH??? Off to do check now!! Back in a mo...

 

[mr. serious]

14.10 volts at idle

 

[jibcl500]

What car is it?
jib

 

[mr. serious]

w208 clk 320 coupe 2000 model

 

[jibcl500]

Sounds like its the MAF then

jib

 

[mr. serious]

But why? Why should it suddenly go, just because I disconnected the battery? And as I said, disconnecting the MAF made NO DIFFERENCE to the running. It was still cutting out at 4000 like it was hitting a rev limiter.

Ian

 

[jibcl500]

Mercs only rev to about 4k in N or P if its only revving to 4k in drive then I would says its the MAF, theres no reason why disconnecting the battery would cause a problem just one of those things. Pulling the lead off the MAF whilst the engine is running should change the running of the engine it would be noticable, if theres no change then the MAF's dead.

Where are you


jib

 

[mr. serious]

Sorry about the slow response jib, had to pop out.

Its not JUST only revving to 4k in N and P, its when driving too.

AND now the engine management light has come on-it was intermittent when I started it up earlier and the car was VERY lumpy on idle, now the light is solid. So I switched off and took the bike!

Is it time to take it to a stealer, or can anyone else help?

Jib, by the way, I'm in Surrey.

Cheers

 

[Parrot of Doom]

Took off the MAF plug (Malcolm suggested in a similar thread) and made no difference. Also, just to note the car ran supremely well before the battery disconnection, so if something HAS gone coincidently t*ts up I would be extremely surprised.

Any info would be (as always) gratefully appreciated.

Ian

If the MAF has failed completely you'd expect there to be little or no difference when unplugged -thats the reason for the test.

 

[jibcl500]

you can get a new MAF off ebay for about £40 if it fixes the problem then youve saved a few quid by not going to the dealer, My dads paying just £115 a hour at the dealer he uses.

jib

 

[mr. serious]

Ok cheers guys. What about the engine management light? Will that go out once the problem is sorted or will this need to be reset?

Also, would it be prudent to buy a fault code reader and identify the fault myself? For example...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=230136643654

Cheers.

 

[jibcl500]

I dont think that the code reader will help. go for the MAF and see what happens thereafter.

jib

 

[television]

There are not many faults that will do this on the 112 engine, the MAF is the most common.

The last one was Omnis 240, that was the MAF

 

[mr. serious]

Just tried my MAF in my work colleagues' estate and performance was down, as I thought it may have just been because its a big old 2 ton lump!! But because I didnt know how his car drove before I had to put his one back in and test ran again. What a difference!

So, yes I shall be almost certainly buying a new MAF.... Although I had similar problems on my Skyline and CLEANED both MAFS and it was like a new car. So with this in mind I brought the MAF in tonight to clean it, but now have taken it apart now to see what exactly I need to clean, as it looks different to my skylines'.

I have found what looks like a diode and after checking it, there is resistance both ways (1.8k ohms), which means that it is no good to man nor beast.

Does anyone know if my assumption is correct? And if so, does anyone know the technical information for this as I would like to see if I can change it and see if I can save myself 55 quid and maybe make Maplins 30p richer!!!

 

[television]

It is not a diode in there, it is a sensor of some sort, perhaps if I pay the postage I could take a peep at it

 

[mr. serious]

Hi Malcom, I'm pretty sure it is, as are my electronics-geek work colleagues!! Have looked on the 'benzworld' forum and found a post by a geek-sounding chap..

''The device in Bazzle's 4th picture looks like a diode. I would assume that the active element in the sensor is a thin film or thin wire anemometer to measure the airflow. Pretty hard to clean unless the contamination is simply an oil coating caught early and not baked on. Most film type anemometers operate with a current through them to heat them slightly and sense the air flow by the change in resistance caused by cooling of the active part of the film by the air passing over the element; doesn't take much accumulated gunk to slow down the response time, and then affect the cooling so much that the sensor gives off false readings.

If you wonder how sensitive these things can be, the ones we made to instrument a turbulence measuring wind tunnel could measure air eddys (vorticity) in the AUDIO range.''

And to back up this bloke's theory is the following technical data info on mass sensors...
http://www.x-desk.net/ximages/21302_pgsi0079en.pdf

I'm not 100% Malcolm, but I'm going to investigate a little deeper anyway, as I have nothing to lose now. If its not a diode, then it has to be a resistor, but it has no resistor markings...?

Ian

 

[television]

Well you could well be right, I will study some of the CPC sensor type devices in the morning