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Can't go up hills?

Minchetty

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Joined
May 31, 2007
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34
Remember that schoolboy joke - my dad's got a Rolls Canardly; Rolls down the hill can hardly get up the other.

Well I recently purchased a W124 Estate 280 4sp auto 155k.
Drove it 300m home without a hitch in one go.
have driven 15m to work and back for two weeks.
Filled up when tank was just below a quarter

Last night I was leaving a friends house and at the end of their road there is a junction on a hill. On take off the car started to struggle and we spluttered to a halt round the corner.

She would intermittently start then stall. The petrol guage was above the last marker before the Bold white line meaning empty. The warning light had not come on. My initial feelings were either no fuel or Gearbox problem - I could get it going occassionally and she would tick over fine. Then I would engage into gear and then it would cut out. I managed to get going eventually (I thought maybe the was an overheating issue) and proceeded about 200 yds and met another hill - managed to get to the top after much spluttering - really felt the engine was gasping for fuel

The petrol station was a matter of 50 yards away, but unbeliviably it had been sold 2 days earlier to make way for a supermarket.

The next nearest petrol station was miles away so I called the RAC.
The Patrol man came and of course the engine started and ran all the way on the towbar to the service station 15m in the opposite direction to where I was going. Filled the car up and he followed for 5 miles (down hill) and there were no problems.

Further on there was a long (not particularly steep) hill (dual carriageway) and near the top the engine started to 'gasp' again.

Pulled over called the RAC. - on turn over it just was not firing.Then afer 10 mins manged to get it going, made up the hill and got home (another 15mi)

Drove to work ok this morning.

Any theories?
Mine (amateur) is that there is rubbish in the fuel tank - when it is nearly empty it clogs the fuel supply.
 
I agree with TV, fit new filter. If not that then fuel pump relay not fully powering the pump.
 
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To go one stage further if you slip the pumps off, emerge the head in a bowl of diesel and run them backwards the amount of rubbish that comes out will amaze you
 
Thanks for your comments

I have a limited mechanical aptitude - is it very straightforward, do i need a Haynes manual or shall I get the local garage to do it?
 
Fuel pump next

New fuel filter fitted, has been fine but cut out again tonight on a hill.

RAC man reckons the fuel pump is losing pressure - Seems to work but then cuts out. So new fuel pump?
 
Try TV's tip first and save yourself big bucks. I have done it a few times on cars with spectacular results.
 
Fuel pump relays do suffer from dry soldered joints, 2 cars fixed in the last couple of weeks with this fault
 
Help

Fuel Filter replaced
Fuel pump relay replaced
Fuel pump replaced

Still cutting out after 20 mins (when warm) through fuel starvation. restarts when cold

Any ideas?
Is currently with local garage
Anyone know an independent around Perth, or does it need diagnosing at a Merc dealer?

Thanks
 
Fuel Filter replaced
Fuel pump relay replaced
Fuel pump replaced

Still cutting out after 20 mins (when warm) through fuel starvation. restarts when cold

Any ideas?
Is currently with local garage
Anyone know an independent around Perth, or does it need diagnosing at a Merc dealer?

Thanks

If you could get it as far as Glasgow, you could do no better than TJ O'Neill (0141 778 5314)
Good Luck!
 
Check breather into the fuel tank isn't blocked and htere are no kinks in the fuel feed pipe.

Try a drive with the fuel cap loose.

Connect a vacuum gauge up to the fuel feed pipe and see if there is high vacuum, then conect pressure gauge after fuel pump to see if pressure is maintained.
 
still running

collected from the garage, took off fuel cap and ran for 50 mins, then stopped. Pressed in the plastic cap to let in more air and started again and still running......

So it could well be fuel tank breather.

I am no expert- where is it? is it in the fuel tank or on the outside?

Thanks
 
Goes from the neck of the tank to under the car.
 
If its not the tank vent then another potential problem which can occur once the engine is hot is intermittent failure of the crankshaft position sensor near the flywheel. If the ECU isn't getting a signal that the engine is running it may switch off the fuel pump --hence the lack of fuel. Got to sure of this because although its easily replaced its quite expensive at £80-£100 ish
 
If its not the tank vent then another potential problem which can occur once the engine is hot is intermittent failure of the crankshaft position sensor near the flywheel. If the ECU isn't getting a signal that the engine is running it may switch off the fuel pump --hence the lack of fuel. Got to sure of this because although its easily replaced its quite expensive at £80-£100 ish


£46 from Bosch, it has the MB pert number one side and the Bosch number the other. It can be checked with an Ω meter, 1kΩ when its good,99kΩ when its bad
 
£46 from Bosch, it has the MB pert number one side and the Bosch number the other. It can be checked with an Ω meter, 1kΩ when its good,99kΩ when its bad


Good tips from television about alternative source and expected resistance values :) but be sure to get exactly the right sensor since Mercedes list quite a few. :confused: http://www.detali.ru/cat/oem_mb2.as...GM=717.440&CT=M&cat=520&SID=15&SGR=075&SGN=04
Remember also the sensor might read OK when cold but try to test it when the fault occurs--this will mean checking out the connections to measure across beforehand and perhaps carrying a multimeter in the car
 
Thanks

Thanks for all your posts - will let you know when it is fixed

Just one further thing I have noticed. I haven't really revved the engine but just did and and it wouldn't go over 4/4,500 rpm - is this significant?
 
No sir, in park or N the limiter cuts in at 4k, this has always been the case
 

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