1969 300 SEL Fuel issues

[Twisted Press]

We recently purchased a 300SEL with a 2.8 litre (M130) engine recently. When we purchased it, it was a runner, but ran poorly and smoked. This turned out to be a head gasket fault which we have now done.

Since the head gasket has been done the car will not now run. We have checked the swirl tank which seems clear, and are currently looking at the fuel regulator to see if this could be the issue. We can get fuel out of the high pressure pump (PES6KL) but it is not consistent, and usually only comes out of about four of the lines.

First thing we want to do is rule out the pressure regulator. Here in the UK we can get adjustable ones very cheap, but we do not know what pressure to set this at, would anyone know?

Also would anyone know what pressure the fuel tank pump should be putting out?

Does the fuel system need priming? If so how is it best to do this?

Any other ideas would be helpful?

[wbain5280]

Your engine has mechanical fuel injection. Fuel is pumped from the tank area to the injection pump and low pressure, approx 5-6 PSI, through the injection pump manifold and back to the tank. There is a fuel filter canister attached to the engine mount under the injection pump. From there it goes to the injection pump via a fuel damper, which you are holding. Inside there is a rubber diaphragm and a spring used to steady the fuel flow. Once the fuel used for the engine, fuel travels back to the tank vie another damper and pipes.

Since you had the head gasket replaced, the plugs, wires and distributor were taken off the engine. They must all be properly aligned. The firing order is 1 3 5 6 2 4 and is cast on the cam cover. The engine must be no. 1 top dead center. Do this by rotating the engine so the crank shows 0 degrees and the camshaft notch aligns with the mark on the cam tower. Then the distributor must be checked and the wire order follows the firing order. The coil must also be connected. Also the fuel flow needs to be checked, as in make sure it is flowing.

Please report back and take some smaller pictures.

The sl113 org site has some excellent information.