Fuel injection problems I think

[natenate]

Please help. my 67 230sl has been sitting in my garage in need of some attention(money) started the other week and it is sounding very rough. Spark leads appeared faulty, very weak spark. Replaced them with 7mm copper core the other day and started the car and it still sounded rough. Shortly after could not get car started. Called AA and they told me that leads appear to be fine and have a good spark. Checked fuel injection pump and seems to have good pressure going in, but when we disconnected the fuel injection lines that enter the engine it was little to no pressure. The fuel was dribbling out. Thought I might have a blockage in the lines so I took them of, but they seem to be fine, I can blow through them. Any ideas?? Thank you for your help 

[Bob Killam]

WhenI purchased My 250 it was running on 3 cylinders after A long rest in heated storage,18 years.My problem was the pistons in the injector that were in the top position stayed there.After opening the top and oiling them they broke free and I was in busines,A very simple and free cure, Hope this works for You!! Maybe A slight tap with A wooden Dowel could be required
                                                                                                                                                                                    Bob K

[natenate]

Thank you I will give it a try

[ja17]

Hello Natenate,

Very small amounts of fuel are squirted at the injectors since the metering is so precise. Remove a few spark plugs and see if they are black or wet. Change the whole set if so.  A fresh set of NGK spark plugs and a quick check of the Warm Running Device (WRD) on the injection pump may save a lot of other more complex tests. Don't hesitate to replace those spark plugs even if they are new. You may need to that several times until you figure out what is causing the fuel fouling. Get back with us for more information if needed.

Bob's advice is good, however don't jump into the complexity of the injection system until the simple and cheap fixes are explored. If you find that one or more cylinder of the IP is not squirting any fuel, then you may have a stuck piston in the IP as Bob describes.

[natenate]

Thank you ja17

 I have checked the spark plugs and they are all black and the first one was wet. in terms of checking the WRD what check should I carry out. excuse my ignorance

[Jordan]

Natenate, the WRD should draw in air when the engine is cold and as the engine warms up it should slowly shut off the air intake.  I find it easiest to remove the little air filter (you can blow into the air filter when removed to confirm it is not plugged).  Start the car and then briefly stick your finger to cover the opening to see if it is drawing in air.  As the engine warms up you should feel the suction slowly weakening until it is gone entirely when the engine has warmed up.  If it is not drawing in air when cold or continues to draw air when warm you know your WRD is not functioning correctly.