Original thread: M103 ('89 300CE) difficult starting solved

I'm still having starting issues. Doesn't matter if the engine is cold or warm. Same symptoms in either case.

1.) Turn the key, slight press of accelerator pedal, engine engine starts, then dies almost immediately.

2.) Will stay running if I keep the RPMs at a minimum of 750 (difficult) or 1000 (a lot easier).

3.) Will die right away if I let up on the accelerator pedal.

4.) If after starting, if I "gun it" to about 4,000 RPM, it will (usually) run as expected.

5.) Engine dies often at stops, or whenever else the engine runs at idle speeds, such as when backing out of a parking space.

6.) I can be driving for an extended time at speeds, say an hour or so; then when coming to a stop, the engine will die. But only sometimes. No definite pattern, but it is happening with more frequency lately.

7.) This one is a new symptom that I noticed the other day, and is easy to replicate. I've noticed that the engine speed oscillates if I keep the accelerator at just the right place. I can watch the tachometer record the engine oscillating between about 750 RPM and 1000 RPM. Constant pattern; up, down, up, down...like a pulsing. I can watch the needle pulse up and down between the two while I'm sitting there. Each cycle takes about a second, but that is a guess, as I didn't time it with a stop watch.

Mechanic thinks it might be an oxygen sensor (or something that I can't remember the name of). Fellow I know thinks it might be the fuel injectors. After describing the symptoms, the immediately said that the injectors were the problem.

After describing the symptoms, does anyone know what's wrong with my baby? Thanks for any insight. I'm almost to the point of dumping the car and getting a Toyota, but don't really want to.

(M103 engine with somewhere around 210,000 miles on it. Can't remember if the injectors were ever replaced. Would have to check the maintenance receipts.)

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Unrelated, when did they change the forum software? I had to re-register and my original post count was lost. Now, it looks like I'm a newby because my original join date was lost. Luckily, I was able to re-register with the same uid, and all my old posts are still here, just the post count and profile didn't get transfered.