First post in this forum -- hi all!

I've got a fuel problem in my new-to-me 300 TE ('88, 150k), which I'd love some advice on.

Boiling the history down:
* Purchased a month ago in Portland from someone who took ok care of it, but didn't drive it much. Got a relatively clean bill of health inspection from MBI.
* Drove up to Vancouver BC, and soon noticed a hesitation on acceleration when cold. Also noticed very high fuel consumption.

The best way to describe the hesitation is that sometimes (often when the engine is cold), when in traffic going at 10-20 mph, pressing the gas pedal does _nothing_ for a few second, as if the pedal hadn't been moved at all. I can't reproduce the problem in park.

* one mechanic replaced the O2 sensor with an aftermarket one, replaced fuel filter, made it run leaner (fixed fuel consumption).

* second mechanic replaced O2 sensor with Bosch OEM one, tested replacement ECU, replacement EHA, adjusted fuel mixture (made less lean). Second mechanic claimed to have solved the hesitation problem, but I'm skeptical. he says there's still a "stumble" which he was unable to fix. I'm not sure what stumble he's talking about (haven't driven it much since, just enough to know the hesitation is still there).

* second mechanic says EHA is leaking fuel (through the litttle holes on top, not by the seals)

At this point I'd also say that the car doesn't feel as powerful as I think it should (but this is my first benz, and I'm upgrading from a jetta, so it's hard to know what to expect). It's certainly not as reliable from a power POV as I'd expect from a well-tuned luxury car.

A few questions for the folks who've read this far:

1) could a bad EHA cause this weird lack of response to the throttle in particular when cold? It seems that EHA problems are mostly associated with bad idles and cold starts. The cold starts are "ok", not great -- sometimes takes a second or two to start.

2) Is there anything else I should be looking for? I've done a lot of searching and haven't found anything like this. I'd love some pointers to any description of how the fuel injection system works, if there is such a thing online.

3) Does anyone have an indie MB tech to recommend in the Vancouver, BC area?

Thanks.

-- David

 

I think that the EHA could cause it. You could try adjusting the EHA an eight of a turn clockwise to try it. Could also be carbon build up on the valves. You may also be able to rectify it with coding a plug adjustment. You need to find out what coding plugs suit your national version though.