Hi niglitz
I have been able to go sor far because it is a spare EHA. But as you may see it on the picture, the little gasket on the internal adjustmet screw is damaged (which would need to be replaced (would cost a few cents). And may be it is the reason why it is not functionning correctly.

Concerning the membran yes that was my question. I know the fuel distributor is likely not reparable. And I wonder whether each single spare of it can be found anywere.

Interesting thread,now that I am reading it I realise what my mechanic was doing.
My problem was that 1 day black smoke started coming out the exhaust which indicates to me unburnt fuel(running rich?).The mechanic started adjusting this gadget you describe and 10 mins later,no smoke!He did have to adjust idle through airbox.
Only side affect he said was that when i floor it(kickdown button)it might feel like the car is starving for fuel and he was right,this does happen.
I was wondering if I readjusted the EHA slightly would it get rid of the starving problem?

I never modified that adjustment on my engine. I prefer to understand before.

My car shows some times the symptom you descride (starving a few seconds and some times engine shuts off). I was never able to reproduce the defect nor found the cause.

That is why I adjusted mine. It always felt that at highway speed and floored that nothing was happening. Just could not get enough fuel. Now with one 1/4 turn I actually can accelerate while going up a slight incline at 75 MPH. Just held its ground before. I think I need one more 1/4 turn, but I may replace fuel injectors first! In a few weeks time. I still think the injectors are not spraying as they used to. I have removed them and soaked them in carb cleaner twice and they still seem to not be getting enough fuel there. I can feel my engine running and others have said I should not. I still can feel it slightly but not as much as a few months ago when I began this insane trip to get my engine as smooth as when it was new. It is almost there!

From what I understand, the internal parts are not available. I've never tried, so I really don't know for sure. You can probably find a replacement O-ring here be sure to get a gasoline compatible material.

There's one way to find out. :) All it takes is a flat blade screwdriver, a 2mm and a 3mm allen wrench and a little spirit of adventure. remember where you started from, so you can return to the original settings "just in case".


Fuelishly,

It worked!My car is back to going like a 24V should.1/4 turn clockwise is all it took,no black smoke and no starving just accelaration all the way through.
Thanx to all.

To those who have adjusted the EHA.

This seems to bring a big improvement. I believe more power means more fuel.

Have you noticed any change in the fuel consumption?

Another question:
Measuring the lower chamber pressure would it help?

300E24V,
What kind of starving have you noticed on your car before the adjustment?

Adjustable on a 420SEL?
 

Does anyone know if the EHA is adjustable on a 1989 420 SEL? Would this procedure work?

Cigar,

I have EHAs from 2.6s, 3.0s, 4.2s, and 5.6s, and so far the part # seems to be the same.

Peter

cc260e,Before the adjustment I had no starving.The car ran perfect.
As for the consumption,I just adjusted it a few days ago and I don't drive it very often but I'll let you know as soon as I find out.

new here, but thanks guys for the great write up so far, lots of great info!!

i don't know much about the fuel system, i took my 190 2.3-16 into a shop, to check out a cold start problem. engine cranks for prolonged period of time when cold starting. throttle must be tapped to get the engine to turn over. it is almost impossible to start the car in cold weather. when the throttle is pressed, there is a slight hesitation before the engine responds. and similarly to the other posts here, the car stumbles for a while, until the engine warms up.

now here is my situation. i described the problem above to the tech. they "worked" on the car for 2 hours, then couldn't find a problem with the fuel system, pump, valves. and stated the problem was electrical. they asked for a couple more hours to look, then they stated they found the problem which was the EHA and that they tried cleaning the screen or something? and it didn't work so the EHA unit needs to be replaced and fuel mixture needs to be adjusted. they quoted me an additional $370 for the bosch part, and including labor hours. around $900 to locate and resolve the problem!!

anyone with insight would be greatly appreciated, does it really take that long to diagnose those symptoms described? am i in a bad jam? thanks to anyone who can help...!!

Water Temp Sensor it sounds like! It tells the CIS-E controller to fire the cold start injector and also lets the CIS-E system know what temp the engine is to adjust mixture via the EHA!

metamorphik - How much are they charging per hour, how many hours for $900? Even at $90/hr., which is rich by my standards, I think the bill is twice what is reasonable. What year is the car? Lookup the part here at fastlane for a fair price for an EHA.

Cruising through Mercedes stuff on eBay, lookie what I stumbled across!! With a "Buy it Now" price of $234, no less!!

http://img.villagephotos.com/p/2004-4/695874/EHA.jpg

Here's the description and, I'll assume, a list of the cars this adjustment technique should work on.


"BOSCH Mercedes-Benz E.H.A. Valve -Governor Kit FREE S/H

This is a BOSCH Mercedes-Benz E.H.A. Valve (2 prong governor kit). It is mounted on the fuel distributor. Fits 190E 2.3 16-valve (86-87), 190E 2.3 (87-93), 190E 2.6 (87-93), 260E (87-89), 300CE (88-89), 300CE 24-valve (90-92), 300E 2.6 (90-92), 300E (86-92), 300E 4-matic (90-93), 300SE (88-91), 300SE 3.2 (92-93), 300SEL (88-91), 300SL (90-93), 300TE Wagon (88-92), 300TE 4-matic wagon (90-93), 400E (92-93), 400SE (1992), 400SEL (1993), 420SEL (86-91), 500E (92-93), 500SEL(92-93), 500SL (90-93), 560SEC (86-91), 560SEL (86-91), 560SL (86-89). Part# 000-070-3962"

Since discovering this adjustment, my gas mileage has increased by maybe 1 1/2 mpg. It's really too soon to tell, only one full tank. But the easier starting & smoother running is so o o much nicer, I'd take a reduction as a trade.

Enjoy,

thanks for the response guys...great finnd nglitz!!


i feel like im getting rammed. $80 per hour and first 5 hours to diagnose my cold start problem! that seems more then excessive. then they told me that i would need to get the EHA. right now im holding off on the install until i can go with a friend of mine to check out what they've done. i don't want to spend close to a $1000 for just a minor adjustment. i will go to the shop tomorrow...but it will cost another $400-500 to change the EHA, they've already charged me several hours for the diagnosis...what do you guys think?

thanks again