c240 poor acceleration.

[stephentanks1]

Thankyou to Television,BlackC55,and jberks for the information.I put a new Bosch unit on and it worked ok.The only thing that concerns me now is that I put the unit on outside the supplier so I could test it on the way home.Engine started ok and you could feel the difference straight away.I had to stop at traffic lights 2 mins later and after 30 secs ticking over the engine stopped.Started again no problem,but 2 mins down the road, again stopped at lights, the engine surged,nearly stalled then settled down.I stopped a few times to let it tick over to see if it would do it again but so far its ok.Any ideas or is this normal.Thankyou again to all.

 

[Glenn Smith]

Adaptation of a new unit, possibly.

 

[jberks]

Check for leaks / solid installation - sounds like air is leaking past the sensor. I'd have thought that Adaption should be pretty instantaneous and not severe enough to stall, though I could be wrong.
Other than that, I'm not sure. My MAS took the O2 sensor with it ,so something to look at perhaps, but if it is still playing up, i'd bit the bullet and get a star diagnostic done rather than keep replacing bits an a maybe basis. Could work out cheaper in the long run.
The star could also reset the ECU which may have an effect too.

 

[stephentanks1]

C240 maf sensor

Thanks for info.I have been out again since and the car seems to run fine now.These maf sensors seem to cause so much trouble.I have had the car two years now and its taken all this time to get it to run properly.The German non genuine maf,from Euro carparts, got the engine to run much better but it always felt as if it was running too weak at initial accelaration.Thankyou again.

 

[star]

You might need to boot strap it which reset the settings and the throtle venturi.

 

[jibcl500]

Star

Give the guy more info please, dont just say boot strap it, he might be out there right now smacking his merc with a welly or something.

jib

 

[MikeMcCarthy]

You might need to boot strap it which reset the settings and the throtle venturi.

Hi Star

What exactly is boot strapping???

nu nu ner na na boot strap

 

[BlackC55]

Boot strap is a process carried out by a Star diag that re-sets everything on the Engine control unit. All of its previous learning is wiped.

 

[BlackC55]

Oh and it works wonders on a car fitted with a new air mass.

 

[jibcl500]

Ref about GSF and euro none Bosch air flow meters, THEY ARE RUBBISH DONT WASTE YOUR MONEY ON ANYTHING OTHER THAN A BOSCH AIR FLOW METER.

jib

 

[MotardMan]

Any idea how one sources the Bosch MAF?

 

[BenzFan1961]

I have a terrible problem of simular nature with my 1984 300SD 5cyl diesel.
It is slow as death on acceleration. and sometimes it looses power going uphill even on mild inclines.
Any ideas what can be done? The car top speed on it's best day is only about 75 miles an hour! this car has only 145 thousand miles on it.

 

[television]

I have a terrible problem of simular nature with my 1984 300SD 5cyl diesel.
It is slow as death on acceleration. and sometimes it looses power going uphill even on mild inclines.
Any ideas what can be done? The car top speed on it's best day is only about 75 miles an hour! this car has only 145 thousand miles on it.

You need to check the fuel strainer in the tank and the fuel pumps

 

[BenzFan1961]

Thanks Malcom,
Are the fuel strainers hard to find/get at?
Also how do I run a diagnostic on the fuel pump please?

 

[BenzFan1961]

Are these cars supposed to be so slow; and gutless on the acceleration?