W210 E280 Misfiring and refusing to rev!!!

[davidbilyk]

Morning!!

My 2000 E280 V6 has been sat on the drive for a while now as it's been sorn, came to start it last night and the battery was dead, annoying as the MOT friend was coming to collect it this morning lol!!

Anyways, MOT guy (a friend) came this morning, armed with his jump leads and a booster pack, put the booster on the terminals under the bonnet, not enough juice to fire it up, lifted back seat up and put jump leads from his car onto the battery, all fairly normal......

The car coughed awake and refused to rev, foot to the floor with the throttle, part throttle, even just a light touch to tease it.... Nothing!!!

As the car warmed up it would accept a little throttle and the revs would climb slowly but with a huge misfiring issue, running on 3/4 cylinders maximum!!

So now I have a big issue, he has managed to crawl the car round to the garage, 2 minutes up the road, fault codes just shows a misfire! I am totally clueless and really need some help!

Thanks in advance guys!!!!

David

 

[BlackC55]

What cylinder is missing?

 

[davidbilyk]

Not to sure, I think it varies? 4 and 6 ring a bell.....

 

[grober]

Change/drain the fuel for starters if its been sitting a while. Regretably you may also have fried some electrics while jumping it?

 

[davidbilyk]

That sounds expensive!!! What could have fried? This is the first time I have ever heard of this.

 

[grober]

Not saying this happened, but modern car electronics don't like being jump started since there are lots of opportunities for voltages surges to occur in the process. EXACT instructions for jump starting are detailed in the owners hand book--- deviate from them at your peril! Try some new fuel first-hopefully might just be that simple.

 

[davidbilyk]

This would happen after I filled it up lol, gonna need some serious jerry cans to empty that lot out!!

I'll give that a try Graeme, thanks.

 

[neilrr]

It would need to sit for a VERY long time for the fuel to degrade to the point where it won't start.

I bought a 190E which had been in storage 9 years which fired right up.

 

[davidbilyk]

Maybe a filter/pressure problem? It was fine before the battery died, now she's a very poorly girl!

 

[johnsco]

Battery booster packs that are used to start cars with flat batteries ought to come with a serious health-warning.
If the battery is flat, but is generally in good condition, the chances are you'll do no harm.
A major problem arises if the battery has been sitting around flat for a long time and has gone high-resistance.
It's almost the same as having no battery connected at all.
In these circumstances, the battery does not have a regulating effect on the output of the booster pack, and you risk applying high-voltage directly to all the car's sensitive electronics.

Say No More !!

Cheers
Johnsco

 

[davidbilyk]

My best guess would be that it had been flat for about a week, I shuffled the cars round about 2 weeks ago and it was fine then?

 

[johnsco]

In which case, that may not be too bad.
BUT ... These booster packs are pretty-brutal and need to be used with great care on modern cars with loads of electronics.
Good Luck.
Johnsco

 

[AndyPCD]

When the codes were read was it done using a merc star machine or an aftermarket code reader.

It maybe either the MAF sensor has gone down or the throttle needs to be retaught back in as it may have lost it where the ca has been sitting for so long but this can only be done from a star machine

 

[jaymanek]

sounds more like either MAF sensor or O2 sensors to me.

To test the MAF, disconnect it and see if it makes any difference.

 

[bolide]

In these circumstances, the battery does not have a regulating effect on the output of the booster pack, and you risk applying high-voltage directly to all the car's sensitive electronics

Where does the high voltage come from in this scenario?

Nick Froome

 

[johnsco]

The booster pack must provide a higher voltage than the battery to be able to power up a car with a flat battery.

I am talking about packs that derive their output from mains power, rather than packs that just contain a 12 volt battery.

Johnsco

 

[davidbilyk]

Howdy!

Unplugged the Maf and no difference, still runs like a dog! It was tested on an aftermarket system. I'll get him to run it again and see what gets reported back.

 

[davidbilyk]

Morning!! I have a mobile auto electrician with STAR going to look at the car today, I'll post up findings later! If anyone needs his number (Nottingham Area) let me know!!

 

[davidbilyk]

Right, star shows no fault codes!!!

Have been advised that this is quite common on MAF failure?? Is this true?

Do I bite the bullet and fit a new maf?

HELP!!!

 

[grober]

If you are convinced its the MAFF then fit a new sensor element and save yourself a bit of money. Here's a how to on a very similar engine. http://www.mbclub.co.uk/forums/howto/25426-howto-mas-replacement-m112-v6-engine.html