77 300D engine cutout (or not)

[Chopper773]

Evening all,

First post so please be gentle!
Just purchased my second W123 a 77 US spec 300D. Everything is generally good but I have a few queries which I would be grateful for assistance. Please bare in mind this is my first diesel.

1 Some of the time (doesn't seem to matter whether hot or not) when you kill the ignition you have to use the stop lever under the bonnet to actually kill the engine. I assume this is the fuel cut off and can be adjusted, but how?

2 Does anyone know any good Merc specialists in the Northamptonshire area?

3 Does anyone know of a company to re gas the climate control?

Thanks all. If anyone has any tips for federal cars like this I'd love to hear them.

Thanks again

 

[piestore]

stop

Hi

No good news, sorry

stoping problem is almost centanly a vacuem leak check vac connections on N/s near battery it is very commonfor these to perish due to fumes from Batt.

Re gas of air con.

It is almost certanly an R12 System ( if it has schrieder type valves (same as tyres) it is) . R12 became unusable by law in 2001 (I think) anyway R12 is no longer available and the system must be converted to 134A and it is quite costley. Anyway how many days do you need A/c in theUK , leave it without it won't do any harm

 

[Chopper773]

Thanks very much.
I'll look for the leak and ignore the AC!

 

[Andy]

Hi

Just to add to Piestore comments. If the vehicle turns of with the key (the very ealry ones used a cable push to kill the vehicle or was that 114) Any way if you look on top of the pump there may be a vacuum diapharm with a one pipe onto it. Check the vacuum diaphram for leaks. Also check the source of the vacuum by the pump. There is a little pipe there which comes of the pump that sometimes breaks.

Good luck

Regards

Andy @ www.mercedesservicing.com

 

[Chopper773]

Thanks Andy.

The injection block has two diaphragms. Both at the bulkhead end, one on top and one on the end. The one on top has one outlet with no pipe connected. The one on the end (which I thought was the cutout) has one pipe connected which goes through the bulkhead. If you pull this pipe off (about the only one with a good seal) it does have some fuel on it which I took to mean that the diaphraghm inside is ruptured and the whole thing need replacing.
Any ideas on the cost of a new part?
Do you know what the other diaphragm is and where it should be connected? I have ordered a suitable Haynes but it's not here yet.
Also I suspect I have a major vacuum problem as the locking doesn't work.

 

[dieselman]

The diapragm unit with no pipe connected is the ALDA. It compensates the amount of fuel for altitude. As the air becomes thinner you want less fuel or black smoke ensues.

The Stop diapragm will be available from Bosh diesel centres if not the MB dealer.

 

[Chopper773]

Brilliant. Thanks very much for that. I'll look up Bosch dealers then! My local dealerships computer nearly melted when they put the chassis number in!