Might be good to address idle first.

Is it set in park?
600 to 750 rpm?

Thanks

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83 500 SEC Euro 198K

I got courageous & removed distributor cap.









Absolutely pristine brand new.
No carbon or burns on cap or rotor
nothing
I just wiped it with a white cloth
Nothing...



So no filing or sanding here.

I lifted it with plugs attached to make it easy.

So it would seem ignition is fine.
Its all replaced under 2000 miles ago.

I found some loose connections mostly from old lights I think or the electronic idle valve.

There is a blocked off small inlet off to the side of the tube that goes under the aircleaner. Looks like it should have a vacumn hose but to where? The main hose goes under the aircleaner. Why would they put a small line into that?
So is the aircleaner above the throttle body? Maybe that line is for the EGR?
Just a wild guess?





The egr is mounted above the exhaust pipies so it has good access



Took pics of idle & temp
Starts right up like a switch
fast.
Idles 1200 to 1500 for first about 5 minutes
Then it settle down to 1000 in park warm at 80C
750 when in drive & 600 in drive with AC

I turned the idle minimally & this seems to be a sweet spot so she idles in her range & isn't going below 600 like it used to with AC.

So shes idling about right for her age.

Mysterious hose is connected to some sort of thing underneath but can't see where it goes

Any ideas?






NEXT?

I left the aircleaner off.
I might try to check the vacumn lines.

So far so good

Thanks ALL

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83 500 SEC Euro 198K

Did you adjust the allen screw on the fuel dist. or the Idle speed with a flat head?
All the advice I gave you will work for sure, but I cannot say for sure it is the best/ easiest route. I am not an MB tech. I just have a car similar and my issues were also similar to yours and that is what I did to resolve it. It worked for me so Ill gladly share how it was done. Others may chime in with better or more knowledgable advice.
I think were in a core group. Some mechanics are not fond of these beasts . These euros are not easy to deal with sometimes. I love the uniqueness . You have to figure a lot out on your own.
Glad to help for once I feel like I'm mostly on the receiving end here on the forum.

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Chris
84 280sl
82 300d euro

Zoned in in idle with a flathead.
1000 in park
750 Drive
600 Dive w AC.

Don't want to play w fuel distrib yet.
is there a way to know when you have it right or the best?


I have to figure out what went into the rubber to the air cleaner

Didn't even eat dinner yet.
This is cosming

Thanks alot for helping down this road.

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83 500 SEC Euro 198K

I'm going to try that vac test with the EGR
I'll have to get the air cleaner attached.

As far as spark plugs one of Enriques guys changed them.
I very much would have liked to have known the condition & if any cylinders were fouled or otherwise comprimised.
I would hope that his guy would report any abnormalities but perhaps I am just too fussy?

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83 500 SEC Euro 198K

The vacuum hoses from the EGR are supposed to go through the WUR or the temp switch/VCV. I would not mess with them. Your trusted Indy has already verified its functioning properly. he is likely right . EGR only works when warm. Like I said its easy to test.

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Chris
84 280sl
82 300d euro

I traced the vac lines.
The line from egr was to the back of the WUR as on the diagram.
Its on one of those 50 valves wiith 2 ports.

I checked for lose lines & the line from the top of the wur to the icv was lose. If you pulled on it it came right out.
The tubing might be a bit small?
I rerouted the line underneath so I could come straight into the opening & I got it to go in tight.

So for all purposes I had a leak in the line to the idle control valve.

I've blocked off the line to the EGR & put a tubing on the EGR.
If I blow I do here a hiss but I hope the line I put on was tight enough.
It line for those air respirators.

I ran the engine & at 50 she did go down in idle & this time the Idle in Park went lower than it used to to just below 1000.

Mind you the egr was open to the tube.

Now I need to double check the test but I blocked the line to the egr & I didn't get any engine slow when it was at operating temp.

I have printeds the egr instructions so here I go again...


I'm glad I don't have to go back into wrong placement of lines.

THANKS!!!

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83 500 SEC Euro 198K

EGR valve popped when sucked on line.
Nice good pop

Engine did slow when I sucked on the line to the EGR.

So I guess its working.

There was no vac at open line to egr but I'd need help with someone accelerating it as I'm not tall enough to reach behind to advance.

I would hope Enrique also tested lien to EGR or this will have to be done in future.

So it would seem the EGR valve is functioning.

Gosh it smelled really bad wo egr attached.
Made my eyes water.

It does have a strong odor.

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83 500 SEC Euro 198K

I did nothing but
1. take off air cleaner & tried to install it with a good connection.
2 Suck on EGR valve
3. Tighten up line from WUR to ICV.
I think the tubing is too narrow small as you can see space around it when it is inside.
It looked like it was inside but pulled out with no resistance

Should I try some tape?








Guages in park before

Car has changed.

Guages in park after

Took it for a drive.

Changes:



RPMs went down in drive to about 600 ish
W AC goes to about 500 rpm

1. I got a lower idle rpm.

2. Economy line went higher

3. Seem to run hotter...when she got home she was close to 100C when she generally runs 90C

4. Seem to feel transmission shift stronger.

Opened up the hood when I got home

1. Hot

2. Tried to tuen icv screw adjustment counter clock to increase idle rpm & I can't budge it. My screwdriver is small & thin so I'll try with a heavier one
but I was able to turn it yesterday.
Are they harder to turn when hot?? Do you have to push down & turn?

3. Checked EGR valve rubber connecton & it was sucked up from base of egr valve from base point where I put it about 1/4 inch.
Obviously it could be hard & leaking.
I tried to chanage this red rubber but I was unable to remove the end from the line so I left it.

I'll have to get this line updated. I guess I could run a new line but its attached to an old thermo plastic switch & those things tend to break easily. Best to get help with this.

It could b e comprmising the function of the EGR//???

A Make sure wur to icv is tight
B. Will have to tune the idle to this setup
C. Then see about fuel distributor.

What controls the economy guage???

Well all in all guess it was a good day!

So whats next?

Hope everyone is having a great weekend.

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83 500 SEC Euro 198K

Sounds like a plan. Maybe I will try to get it close myself.
There is a hole on top thru aircleaner that I think gives access to that allen port. Have to stabilize the icv vac first.

I do have 8 new fuel injectors on hand for when new ones are called for.
Might just pay to have someone put them in if mine are a problem.
Maybe I should put that on the front burner before doing cats?

I let the engine cool & I was able to turn the screw on the
icv.
Guess it has a really good vacumn this time.

The air hose leading to under the aircleaner is not that tight either but don't know if that is that important

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83 500 SEC Euro 198K

Don't assume this is a massive problem. Your O2 sensor and cats are probably OK. However, your engine is not running properly as evidenced by the fact that the economy gauge is not pegged in park at operating temp. You need to replace the vacuum lines and hoses especially the larger rubber tubes to and from the idle control valve. These are old and deteriorated from the pictures. Any air leaks here bypass the fuel distributor and are not compensated for causing poor running and bad exhaust emissions. Once this is done the fuel mixture and idle rate need to be set properly. Even without instruments an experienced mechanic can adjust the fuel mixture on non-stabilized idle rate engines by engine smoothness, vacuum and exhaust smell but adjustment by instrumentation is certainly preferred.

Disconnecting vacuum to the EGR valve and plugging the vacuum line should not cause a difference in engine performance or exhaust smell---this should only occur when vacuum is applied to the EGR valve.

Finally, the corrugated pipe appears to be the remnants of the Webasto heater that was removed when your car was converted to US spec. Assuming this pipe is connected to the exhaust system pre-catalyst it should be plugged to prevent fresh air from entering the catalyst and negatively affecting NOx emissions. If it is connected post-catalyst, leave it uncapped---it may dilute the exhaust to your benefit. Mark

WOW Econ G has never been pegged in park on idle.

You mean the large 1 1/4 inch rubber tubing as well as all the skinny vac lines? (I changed out all the flex soft rubber connection when I got it as well as all the old fuses just in case.

Enrique was able to turn the idle when the engine was running at operatin temp.

I am almsot sure that getting some sort of seal to the WUR to idle control valve made turning that screw on the icv hwen hot almost impossible.

I waited & went down when she was cool & it turned freely

So guess as its understandable she needs for attention to vacumn
but I had hoped this was ok.

I also never got to change (for fear of breaking the plastic connection the rubber on the tubing from the back 50C temp switch to the center near the fuel meter area.

I think part of my problem was MB parts Keyes did not have a correct rubber connection for the top of the WUR. Its a very large end to a smaller end.
I got the size to fit the WUR but I think I had to compensate with thinner tubing for the smaller end & was hoping it was fine.

When I got it this rubber on top of the WUR was badly cracked broken
so no wonder it had problems.

This is a good direction but I can't get to those vac lines that come from the throttle body.
Are they under the intake?

Who can help with this. Like I said even the tubing to the EGR & its rubber connection is old.



Yep, this is the way my Uncle & brothers did it.
I am grateful for watching them fix cars since I was 8 years old someone was always under the hood.



Then it must have been the tighter connection of the WUR to the idle control valve & it was bad!



She did have a special timer heater that would heat the car for you so you could get into a warm car in comfort...great for German winters. The controls are in the dash but I guess the heater is gone?
Anyway guess its not all that useful in CA.

From what I can see underneath look like its likely pre cat...
Again how come no one ever wondered what they big hole was for? Have to fugure a way to cap it.

This is what is underneath connected to the tubing



I wonder how far back it goes? Would it have had to find a way into the car to heat it? I guess if I knew more about the unit one could try to take it off if that would be suitable.

Well, this has been very useful but I wanted to run it & I am not sure how its running. I took it out last night so I couldn't really see instrument [panel that good. It is very dim at night & it doesn't seem to get bright enough even with adjustment.

I did notice the change in economy guage & idle & it felt different on the road.

Wow, Still did not realize the economy guage should be pegged???


Sorry, silly ? is pegged 0 or in red line. Now I am confused...is the best economy in the 0 range opposite of red. Thats what I have assumed as economy goes more toward red at aceleration.
Should I assume when I get it to approx 0 in idle in park that its got a good vacumn?

Thanks a bunch!!!



This is a pic in park at operating temp taken by the seller...
Economy guage is not in fuel view but looks like it might have been nearer left/// lower on the guage.
The car has been setup with vac leaks so it might be running worse than when I got it?



This is a pic as it has been running on setting for past few years
which appears to be worse economy


We have to also keep in mind that the old cars idle higher in park.
Its ideling at 1000 rpm so it would seem normal for economy guage to be higher????

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83 500 SEC Euro 198K

Need to get alot of parts for vacs
which is always a problem w a euro as #1 there was no 83 500 sec in US
I tend to have to switch searches between 83 380 & 84 500

As if the euro wasn't bad enough the nightmare is the icv is modified so I can see why a mechanic would have a problem.

Problem is 1 I don't have a electronic icv so thats trouble.
Believe I have an air slide valve used in if I recall the 450 SL? Guess I will have to get part numbers to get right rubber replacements.
This loks like what I have from a 80 450 slc





Why are two ports on top blocked w screws?
Where should these go?

I suppose one could try to return it to the orig electronic idels control but they are $$ & not sure what else is missing.

It would be nice not to get gased when on the road


This is the 84 breather hose

It has that extra line that I don't know where it is supposed to go as its plugged on mine.


If I look up the 83 380 breather hose its much different than mine...
So I have been searching for hours tryign to figure it out.

i should have no proble w installing
New beather hose
valve cover to icv hose & rubber seal under airtake housing ( tis one seems to be pliable.

Would this really help?
Are the hard old hose bad?
Also some vac line I can do.

Guess its all a step in right direction.


Say vacumns are not tight...
What do I do to run it say today?

Idle has gone down w increased vacumn to ICV.
If I increase idle to compensate do I have to lower the fuel ratioi?
This would lean it out more so I'm confused.

Guess its good I haven't used it too many miles with all these issues as maybe there is hope the cat still might be alive.

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83 500 SEC Euro 198K

Spending hours trying to find the right parts
Be nice to get her all dressed up in her Sunday best but
I need to get to pass smog test asap.

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83 500 SEC Euro 198K

Been working on checking line cond sizes mostly 4mm to 6mm black.

I looked inmy arsenal & had a new egr red rubber which I could never install as the part on the vac line was seized.



Hooked up a hairdryer & a few minutes of heat & shizam

Open sesame
I got the rubber off...

Upon inspection it had cracks where is was on the EGR valve
hence thats why it was getting sucked off.



I can change the egr line in future but if it sucked off the rubber likely its ok...



Going down to check idle & armed w a 3mm hex will see if I can get it better.

Can't get it worse.



Also looks like I need a rubber hose from valve cover to intake as its lifing easty on intake end.

Rubber hose & ring under air cleaner see to be ok.

Hopefully the EGR will now do its job for the cost of a $3 rubber



Thanks for helping me along & wish me good luck!

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83 500 SEC Euro 198K