Well, I promised I would up-date as to the benefits of all the well-intentioned suggestions and advice. Unfortunately...I've no good news to report so far.

I ordered from Fastlane, received and installed brake stop switch, neutral safety switch and air intake temperature sensor. I removed MAF screen and did a thorough cleaning of the hot wire sensor. (Even bought a magnifying glass for this - an idea sparked by Jim F's website).

Despite these 4 separate actions - the CEL continues to come on and I continue to pull DM codes 4 and 25...and pull them in same old cycle (start car 3 times - comes back on the 3rd ignition re-start. Incidentally, I've discovered that is it not necessary to achieve this by driving the car - or accelerating. Simply re-starting 3 times results in the CEL on again and the codes re-appearing).

Upon the last switch replacement not working, I did a exhaustive wire examination. I discovered severe insulation cracking and loss on the sensor wires that are part of the alternator/starter harness. The sensors are not ignition related (oil temp and level I believe) but since they go to the module box, I figured possible shorts...so I tore the old harness out, rebuilt it, and re-installed it. (A 4 day job). No change.

I haven't had a moment to get my code reader back into the diagnostic plug - might get a chance tonight - so I can't report the change yet in the other codes.

In the meantime...I guess I'm asking if anyone has a thought to where I should look next, BEFORE removing and examining the throttle actuator.

Someone (Dean? Larry? Jim F?) suggested I look at the pre-air pump and valves? I have not yet done this...primarily because I'm not sure HOW to diagnose a blockage or problem.

Which reminds me...with respect to the ETA - when I turn on the ignition, I believe I hear it reset. I mention this because I did a thorough re-reading of Jim F.'s dialogue on this topic, and I recall Jim saying his did not re-set. I'm pretty sure mine is. But this doesn't automatically mean my ETA if operating perfectly, does it?

By the way...my symptoms (other than the CEL and throwing codes) is that the car does not accelerate under load from a low RPM state. The car is great in mid to high RPM when moving... but from a standing start, and giving it gas...you can tell the engine is not performing well. From my carb days, it's similar to not enough fuel, or not enough air. (Which of course is the same thing here - just electronically I guess.)

One more thing: Despite replacing both the brake stop switch and the neutral safety switch (AND replacing every single fuse AND every single outside lamp) - I also continue to have the outside lamp warning light come on and stay on. And this is curious: it comes on only when the brake pedal is touched AND the gear shift knob is moved from the "park" position. Curiously, it doesn't come on if either of the above two are done alone - it only comes on if the brake pedal gets pushed AND the knob is moved/shifted slightly to the right (from the resting "park" position).

Well, quite a novel, huh? My apologies for my long discussion, but I'm almost out of thoughts of what to look at next, so I figured a clear head opining might help.

Thanks!

Jim V.

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Syntax26

1995 MB E420 (lowered)
1989 MB 300SE (sold to brother)
1975 MB 280 (sold)
One damn fine jacked-up golf cart