MichaelBrown

I’ve posted a few times about my 93 190 2.3 and all of its fuel related issues. Well I’m happy to report I have resolved those issues.

I’m down to what I believe hopefully is the last issue and that is the throttle linkage set up.

The set up I’m describing below is with the EHA valve disconnected.

This may be a little difficult to explain but I will do my best. In the photo, I have the Bowden cable adjusted to the point where the throttle begins to open. As you can see, it’s about a half inch from the thrust micro switch.

With the Bowden cable adjusted to the point that it depresses the microswitch, the throttle will engage with the gas pedal almost all the way to the floor. In this scenario, the RPM will jump from 800 all the way up to 3500 RPM if you as much as touch the accelerator and you have to shut the car down.

in the photo, with the Bowden cable adjusted to the point just before the throttle opens, the accelerator pedal functions normally with the exception of that if you punch it and let up on the gas pedal very fast, the car will stall.

it is possible to adjust the cable to where the lever is just resting on the microswitch and this also seems to work relatively well except at the microswitch is never depressed.

any suggestions?

dolucasi

What you are describing Michael is what I believe is a weak point in at least the 2.6L throttle linkage I have.
Drove me nuts that the play between when the microswitch is activated and the throttle plate starts to open is too much. Mine was like 3/8th -1/2inch at the throttle pedal.
Adjusting the throttle cable will not solve this problem at least in the 2.6L linkage which is a different design than yours.

And that gap is very undesirable in a manual transmission car where you need to rpm match during shifting. Not so important in a auto transmission car.

When my car was new, the gap was much smaller but that mechanism has been actuated 100's thousands of times by now so most parts in it is worn, naturally.

For the 2.6 the most important part is the white plastic like bushing/roller that rides sideways (or up and down on yours).
In my case, replacing that bushing with a new one helped (still available at the dealer as of 2 years ago) quite a bit but still was not satisfactory for me.
So I hand made another bushing that is slightly bigger in diameter than the factory. I'm back to the original spec's I think and am now satisfied. The play/gap is now maybe 1/4 inch or less.

How many miles on your car? See if it looks like the roller for the throttle actuator on yours should be replaced.

I hope I am not misunderstanding your description above.

- Cheers!

MichaelBrown

I think this sums up my issue quite nicely. I will look at that bushing. So this car has 200,000 miles on it and I never intended on making it run. I actually bought it when I was learning how to do automotive refinishing ro practice on. The car turned out so nice that I decided to go ahead and get it running instead of sending it off to the junk yard. Since I bought that car a few years ago I’ve acquired several more 190s including 2 2.6 cars. I’m convinced that all of the fuel related issues and the throttle issue or why the car was parked and destined for the scrapyard before I got it at auction.

dolucasi

Looks nice Michael. These cars as you have probably found out need a lot of tinkering to have them running perfectly. I see a collection of 80's/90's Benzes in the background of your photo.
I was fortunate to purchase my car new, use it for 13 years, 125K miles as a daily driver. I sold to a friend who wanted a manual W201, pretty cheap I must say.
He was kind enough to return the car to me at 27 years, 175K miles. Now it has 200+K miles and I can say after a lot of work it finally drives as well as it did when I drove it off the showroom 32+ years ago. I will get there once I swap in a newer rear differential from an auto transmission car which are a lot easier on the diff's due to the torque converter.
I have the backlash-free diff in my hands ready to swap in when I get a chance.
I still have the original clutch and the original rear break discs in it (still within spec).

On your linkage, manually actuate it and see how much it has to move before the throttle plate switch activates. Because that is not adjustable as I said (for good reason) the roller on the top in your case maybe worn.

Let us know what you find out.

- Cheers

MichaelBrown

I discovered that there is an adjustment screw on the back of the lever that allows the assembly to move forward or back of the thrust microswitch. I adjusted that up and now it’s presses on the microswitch as it should. I was able to adjust The mass airflow sensor and it is now in spec.

I was messing around with the duty cycle trying to get it at 50% with no luck yet but the car is starting right up and running although the throttle is still acting weird so I still have tinkering to do

dolucasi

Good to hear you made progress. Did I understand corerctly? You were able to move the microswitch mechanism back and forth with an adjustment? A close-up picture would be great if you can take one.
BTW, not sure if you changed the color of the car but you picked a great color, or it was a good color to begin with.

190Efan

Glad you saved another 190 from the junkyard. It's looking really nice. A Haynes manual would be a good investment and they're not that expensive, about $25.00. You want to be really carful with any adjustments as they can really foul things up even more. You might also want to talk to someone at the MB Classic Center as they can tell what everything what set at when your car left the factory. It's likely that a previous owner ,might've done some adjusting and that could be why your car is off now. Just my 2 cents.