Wow,
I just started having this same problem. My glow plugs took about 8-9 seconds to warm up before I could start, so I replaced 4 of my 5 glow plugs. I replaced four of them because that is all I could get at the auto parts store for the time being. I didnt get the furthest glow plug away from the front of the car. Now, my car had a hard time starting and stalled after a couple of seconds. I had to step on the pedal the second time to get it going and to level out without stalling. When it is warm it starts up right off. Could this be the last glow plug?

Also, could this have anything to do with the battery dying? I replaced the voltage regulator but the battery died again the other week. Could this be the glow plug relay messing up or does this not have anything to do with the rough starting issue?

Thanks

DK

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1983 300sd 253,000 + 13,000 (10,000+ on veggie and biodiesel)= 266,000
1983 300sd 390,000 (Leaky windshield seal) Known to me as the shower car. Parts car now!
1 junk 300sd Watch out for the skunk that lives underneith it!