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Q: Down one chamber

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Car stopped running the weeks ago while on the road and wouldn't start, I replaced the fuel filters and injectors but when I start I've lost one cylander (also before replacing injectors I was down one chamber but could start) I've also noticed I'm running too much oil (my mistake not a symptom) how can I get it going again? I presume it's electrical/glow plug related

My car has 200000 miles.
My car has an automatic transmission.

I owned a 300D and 300SD, both 1983’s. You can have a bad glow plug or two even if the glow plug light is lighting when you turn the key on. The easiest way to determine if a glow plug is bad is to ohm test the circuit. The relay is a large black box located behind the drivers side headlight. There is a large red (power) wire and two plug connectors. Also, there is a metal strip held in place by two screws. That is actually a strip fuse. If it’s cracked or broken, replace it. Do not simply substitute a piece of metal!

Unplug the larger of the two plug connectors. That goes to the glow plugs. You will need a multi-meter set to ohms. Connect the negative from the multi-meter to the battery. Probe each wire in the connector with the positive wire. A good glow plug will read anywhere around 1 ohm. Anything substantially higher than that indicates either a broken wire or bad glow plug. Bad glow plugs are much more common.

If you are still not getting fuel in one cylinder then crack each injector loose one at a time. Whichever cylinder has little or no effect on the idle quality, is the one not getting enough fuel. You can pull the check valve on the injector pump for that cylinder to make sure the piston is moving up and down. If it is, then there may be a blockage in that fuel line.

If you’d like a fresh pair of eyes on this, consider YourMechanic, as a certified technician can come to you and diagnose the starting and cylinder issue firsthand. They can then suggest an accurate fix from there. Best of luck.

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