Does This Fault Sound Like Fuel Starvation

[AGT]

This past weekend I drove my Pagoda from Edinburgh to its new home in France. I had been really looking forward to the drive  and had planned a great route through Burgundy and then down the Route Napoleon but it turned into a bit of a nightmare. My car is a 1966 230 SL manual 'box and was fully serviced and running perfectly before I set off.

Day one - Edinburgh to Hull (about 270 miles).

After about 220 miles and showing less than half a tank my car started to cough and splutter, lost power and then stalled. It would not re-start. The car was picked up on to a tow truck and unloaded at the next service station. It started first time of asking and I put 44 litres of fuel in it (so the tank had been at about one-third). The car then ran perfectly for 10 miles and then the same happened again although this time it re-started immediately. And then after about another 10 miles, the same again. I eventually made it to Hull with the car spluttering/coughing intermitently but always clearing. I decided to board the ferry and continue my journey.

Day two - Zeebrugge to Tournus (about 500 miles)

I abandoned my chosen route and decided that I needed to stick to the autoroute with its hard shoulder and frequent service areas! The car drove much the same as the previous day with lots of spluttering, then a loss of power which cleared each time. It was just as frequent going downhill as uphill. I refilled the tank about every 100 miles. On one very long and steep ascent the car spluttered, lost power and stalled. It would not re-start for about 30 minutes but did so after a lot of rocking to slosh the fuel about a bit.

Day three - Tournus to Tourrettes sur Loup (about 350 miles)

The car drove perfectly all day. Not a cough or a splutter.

I don't think that there was anything wrong with the ignition. The spluttering was not backfiring; it was more like a deep cough which shook the whole drivetrain and there were no clouds of smoke as the car cleared and power was restored. My theory is that on day one I ran the tank down much more than I ever had before and that I clogged the fuel filter with gunk which was picked up from the bottom of the tank.

Any views or diagnoses?

Best regards
Andrew
1966 230SL

[twistedtree]

It's tough to say, but fuel starvation is certainly a strong candidate.  I'd suggest changing the main fuel filter (the big one my the engine), and removing the strainer plug from the tank which will require draining the tank.  Pay particular attention to the strainer and the immediate area inside the tank.  If there are rust particles or silt then the tank needs cleaning or replacing.  If it's just silt, a good cleaning will probably do the trick, but if there is rust you should probably bite the bullet and replace the tank.  Also check to be sure the fuel return line from the injection pump is not blocked.

If the problem persists, at least you will have done a thorough fuel system servicing....

[JamesL]

That sounds like a great drive with a lot more stress than you'd have liked - which is a pain as I am sure you'd planned some great roads etc

Perhaps you car hates Hull?

[George Des]

You might also want to check the gas cap to ensure you are using the correct type.
Can't recall off hand if it is supposed to be vented or non-vented, but using the wrong one may cause these same type of symptoms.

George

[glenn]

What a great drive route!  The next time it will not start, squirt some gasoline or Quick Start' into the intake.  If it runs smoothly, you probably,  have the classic build up of crud blocking the square hole around the return fuel line where it goes into the plastic basket in the bottom center of the tank.  The crud stops gas from getting into the basket and into the electric pump suction line.  Clean the three gas filters(?).  Clean the tank. .. Amateur Pagoda-0-logy.

[Jordan]

If you are draining the fuel tank you might as well check the filter inside the electric fuel pump while you are at it.  You don't necessarily need to drain the tank to do this but since you are working back there anyway.

[simonbaker]

I had almost exactly the same scenario a good few years ago - turned out after a very frustrating trip that it was the main fuel filter (positioned on the left hand side of the engine bay on a RHD Pagoda), I changed it (it had obviously not been changed for a long time) and have had no further problems.  Basically the fuel pot with filter in it starts full, you drive down the road and eventually there isn't time for the pot to refill as the engine consumes petrol and the engine cuts out.  You stop.  Then you play around with this and that under the bonnet for a while and by then the pot is full again and the car starts; you scratch your head and guess you did something that may have cured it, set off again and ten minutes down the road same thing again...
Short journeys particularly in town, where fuel consumption may be lower are quite often not affected so you only notice it when you let rip on the open road.
When was a new filter fitted?
Hope that is what it is because it is a straightforward job.  You could always take it for a drive on the open road with the filter removed to see that it runs OK.

Simon