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Very Good.

I had a decent Collection before retireing, but strickly Benz .

This is one of the 113 chassis I kept..it is here in Fl now as a daily driver, where it belongs.
That is an old NH pic next to my Barn, but those cars don't belong up North if you like to drive them as much as I do......so, I brought this one down here and now I can leave the Hardtop off and drive it year-round.
I kept this one b/c it is an Early Euro version 250SL w/stick that I have owned for many years, so I am partial to it. I have owned all versions of Pagodas and they are kinda my Forte, but this version was my Fave....and the rarest in production #s.
They are coming into their own finally, but nothing like some of those Muscle Cars...

http://members.aol.com/ajdalton7/113sl.jpg

Hi Arthur,

I hope you had a good day! I guess it was hot today down in Florida? (it was up here in Pennsylvania - I guess the hottest day of the year so far).

Thanks for letting me see the picture of your car. I've always had a particular liking for the MB 2 seater convertibles - ANY of the models. But I never had the money to get one - and then when I had the money - I didn't have the time (worked too much). Closest I ever got was a '67 MGB-GT that I restored many years ago.

What did you do before you retired?

Well I got home and ran some tests. First off...please ignore what I said about 5 volts at 85 & 86. I got 12v today - checked it 10 different times - always 12v. I turned the car off - and there was 5 volts. So - I must have been tired last night and reported 5v when the car was off. My apologies.

I jumpered 1 and 30. Clutch got powered (pump ran).

So...it would appear to be the relay. I ordered one and it should be here tomorrow. I have my fingers crossed that once installed - the pump will run AND the 2 codes I get don't come back upon the 3rd turn of the ignition (which is the pattern...I know it by heart! Ha Ha!)

Anyway, I should be able to report the results tomorrow - pending receipt of the relay.

Hope you have a good evening!

Jim

__________________
Syntax26

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

Hi Arthur,

How are you doing? Hope all is good with you.

Well, unfortunately I have bad news and worse news to report.

I received the replacement relay today. I put it in, checked that I'd left no wires un-re-attached, and started the car. The pump clutch did not engage.

I cleaned the female sockets to the relay -still no pump clutch.

I then removed the relay - jumped the load relay sockets - the clutch did engage.

I tested voltage at the coil sockets - with the engine running - 4.5 volts!
(So my self-critical comments yesterday about having read 5v with the ignition on, engine off - I was wrong. I did get 5/4.5v the other night.)

So I suppose this means the coil is not getting energized (low voltage situation)...but I just spit this statement out -quite frankly, I'm not sure of anything at this point.

Anyway...upon the 3rd ignition cycle - CEL came on, and the same 2 codes returned (Pin 4 = Code 11 = Open circuit secondary air...& Pin 19 = Code 4 = air injection system faulty).

The above is the bad news. Here is the worse news - coming from my attempt to test drive the car AFTER the above.

For the few weeks I experienced the CEL and these codes - at least the only "performance" symptom was that the engine did not accelerate well from standing stop to mid-rpm's.

During the test drive the car went into what I believe to be limp home mode. I use the word "believe" because I had never experienced this on the car before...I've only read it here on the forum and in manuals.

The symptoms were:

1. The throttle pedal became unresponsive
2. The engine would not rev - it would choke
3. The situation cleared up by cycling the ignition (i.e. turn it off, turn it back on).

So...that is that. I'll put my thinking cap on and read some more to see if I come up with any ideas.

If you'd like to throw a thought my way...I'd appreciate it. Naturally, I don't want to impose upon you, so if you're busy, I understand.

Anyway, thanks for your help so far.

Take Care!

Jim

__________________
Syntax26

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

OK

You have conflicting info here .

Here is a post ..is this true??

>>

Also, is there any signs of bad harness insulation anywhere??

..and lastly, take your V meter and give me a V reading at pin #2 of the 38 pin connector ... meters + to pin 2 and - to engine ground w/key ON.
No jumpers or anything like that..I just want a reading ...

Also , did you clear the codes after replacing the relay and did the new relay have any V rating.?

__________________
A Dalton

Arthur,

Hi!

I. Relay Voltage: As to the different voltage readings, this is absoulutely true: With engine on - sockets for relay pins 85 & 86: yesterday I got 12 volts, today I get 4.5 volts.

II. Wiring: My engine harness is less than 12 months and 5,000 months old. About 2 weeks ago I replaced the harness that transmits signals from oil temp and pressure sensors (and 1 other sensor). I replace this because there was significant insulation breakdown.

I've looked at just about every other wire on the car - they look ok.

III. Pin 2 of 38 pin socket: 12 volts (I grounded in socket 1 of 8 pin socket - fyi). Key on, engine NOT running.

1V. Code Clearing: Yes. I actually cleared both codes last night in anticipation of receiving relay. Codes return in normal fashion (3 ignition cycles). I cleared them again.

V. Relay voltage: Just like the original - the replacement is rated 12 volts. This is stamped on the cover.

******

Having said all of the above - something I've never mentioned: While the relay has 5 pins, the relay receptacle only has 4 live female sockets. The extra pin is labeled 87a (possibly a for "auxillary" - as there is a live socket for pin 87 (just the number without "a").

Well, thats the info you asked for. I really appreciate your help. Because I'm stumped, frankly.

Thanks!

Jim

__________________
Syntax26

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

>


OK

That is good.

Now. I want you to change or check fuse # 6. Make sure it has a good connection..
Then I want a voltage reading from pin 4 where the relay plugs into [ that will be relay pin 86 ... Do this with key On and relay unplugged..

Do the same at 85 too, just for kicks

__________________
A Dalton

Arthur,

1. Replaced Fuse 6: With relay in - clutch does not operate.

2. Pin 86: Grounded in 1 of 8 pin connector - key on/engine off = 12 volts

3. Pin 85: Grounded in 1 of 8 pin connector - key on/engine off = 0 volts

4. Meter Positive in Pin 86 - Meter Negative in Pin 85 - key on/engine off = 4.5 volts

So...by moving keeping positive of meter in Pin 86 - but moving negative of meter from 8 pin connector to relay pin 85 - voltage drops from 12 to 4.5 volts

Jim

__________________
Syntax26

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

Ok

So, we have a good circuit until we get to the N16 module . This is Base Module . It is over by the other modules on the passenger side firewall, engine compartment. It has 4 fuses ..check each one.

Also, I suspect a possible ground problem and that is why I asked for engine ground, but you keep using the #1 of 38 pin..I don't want you to do that..my test are very SPECIFIC and have logic that you don't understand, so please follow them as I write them..read them twice if you must.

So, check the modules fuses and also check those Brown ground wires on the chassis.

Also, go back to the post where I listed the criteria for AIR . You will not get a pump until those are met and that info is transferred to the N3/1. The BM is powered by fuse 6 and the modules internal circuits are protected by those 4 10A fuses, so they need to be checked next.

__________________
A Dalton

Hi Arthur,

Today was a 13 hour workday - setting up for the car show, so I didn't get a chance to get to the car until late tonight.

BM: I had previously checked these 4 fuses, but went back again and check VERY carefully. All 4 are good.

Ground wires: On the understanding you are referring to the 3 separate screws at which a total of 8 grounds are found - all near the module box - 2 of the screws into the upper strut support and 1 into the module box itself.....I removed all 3 screws - cleaned all connections and screw threads - sanded surface oxidation for contact areas - reinstalled. Also - inspected all wires - no breakage or other damage found.

On the understanding that there might of been a grounding problem, I tested voltage before and after.

BEFORE inspecting/cleaning - key on / engine on:

1. Pin 86 to ground screws = 12 volts

2. Pin 86 to pin 85 = 12 volts

In light of #1 and #2 above - I reinstalled relay: clutch did NOT come on.

AFTER the relay re-installation test:

1. Pin 86 to ground screws = 12 volts

2. Pin 86 to pin 85 = 5 volts

I THEN did the ground screw inspection/cleaning = same results, i.e.

1. Pin 86 to ground screws = 12 volts

2. Pin 86 to pin 85 = 5 volts

This is the data and results of what you requested I check.

BUT - just to be sure that in the interim I've not screwed anything up with the load circuit....I put in the old relay (still cover-less) - manually closed the contact = clutch engaged. I recite this just so you know that the pump itself, and the circuit from the relay to the pump - is ok.

***

The fact that sometimes 86/85 is 12 volts - but at other times is 5 volts - and yet the results (no clutch) are the same = puzzles me.

***

As to you statement about criteria for AIR. I will re-read. Let me say I do comprehend generally (in other words - I know the pump does not run all the time) but I do not comprehend all of the specifics of the criteria. And...I would like to understand this. So I might ask you to explain this to me again, but I first re-read, and then try to learn it on my own before I ask you to take the time to re-explain.

So anyway - please know I sincerely appreciate your help, your time and your advice with this issue.

I hope all is going well for you.

Jim

__________________
Syntax26

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

Arthur,

As I re-read the criteria for AIR...I noted your question related to the 5 volts at coil input going away when coolant temperature went.

Tonight's data yields the opposite - although I don't mean to suggest there is a cause & effect relationship. But tonight I had 12 volts at first - but later I had only 5 volts. One could presume that the coolant temperature would have increased - if it changed - after the engine ran a bit. (The point being I got 12 volts at a time when the engine had sat cold overnight.)

I just thought I'd point out this fact. I'm not sure it means anything or helps get to the bottom of this. But one never knows, right?

Jim

__________________
Syntax26

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

< >>


Yes...
If we have 12v at 85/86, then the relay has to pull in UNLESS we are loosing it when the relay is plugged back in..

The N3/1 terminal 19 is the ground end of the circuit and that is where the switching is done...but in order for it to switch [ and therefor complete the circuit] it has to have the criteria met so, the engine has to be cold ,the rpms have to be idle or slightly above, and the MAF has to be satisfied with air flow spec. That is why I asked if that 5 V went away when the car was warmed up. It may be that when the old relays coil shorted , it did some damage to the switching transistor driver circuit in the module..I do not know that.
Can you confirm you have 12v to 85/86 when the relay is plugged in ??
maybe some back -probing.. you should only get 12v when the car is COLD..and the engine has to be running...

__________________
A Dalton

Arthur,

I will try to test the "losing 12 volts when the relay goes back in" idea. Naturally...I have to have 12 volts to start the test - and this isn't always the case. So I might not get this condition tonight - I may have to wait until tomorrow. But I'll try.

I think if I jumper run some wires out from the pins, I can take a reading.

As to the criteria, I totally understand the first two - coolant temperature and rpms. But a question or two if I may about the second two:

1. What do you mean the MAF has to be satisfied with air flow? I presume "sufficient" air flow (as compared to "too much"). This input signal comes from the hot wire, correct?

2. Lambda being in open loop: I am not sure what even to ask about this. I had always thought it started in open loop - and went to close loop after a short period of time during which the O2 readings were made, and if said readings were within a pre-specified range. Is this correct?

Well, thanks again. I'll go out to the car and see if I get 12 volts and can try the "relay installed" test.

Jim

__________________
Syntax26

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

So many questios..but here is the deal ..

If you have 12v at those pins , then the criteria has been met.

So , is the 12v dropping b/c the BM is defective and loosing it ???

Or do we have a bad connection under the relay , or even the relay feed wire [terminal #19-gy/wt wire] at the Control module..[N3/1]
See where I am going here??

I would tie a couple of back probe wires on 85 and 86 and then put the relay in. I would then start the cold car and monitor those wires with your meter..if 12v is apparent and the pump does not come ON, the relay is not pullin IN ..simple as that.. and if you get 12v and it drops as soon as the relay tries to pull in, we have a bad connection somewhere between the relay and N3/1, b/c we have traced the circuit up to that point. [ that is what all that pin 2 and 86 to ground testing and stuff was all about. ]


Anyway, to continue..............................

I would verify the relay and I would verify the 12v.

On your other questions..open loop is the 02 sensors has not heated up enough to trigger closed loop and the AIR systems criteria is to STOP working when the sensor goes into closed loop.[ meaning, one of the AIR systems operation criteria is OPEN LOOP must be the condition..as stated in my criteria post] If No open loop, then no AIR.
The ONLY time the AIR comes on when 02 sesnor is in closed loop is when the Emmisions self test is done..and the reason they do it then is b/c they need a reading from the 02 in order to see if the exhaust goes LEAN when the self test energizes the pump for testing..if the 02 sensors was in open loop , it would not know what the exhaust condition was...OK???

Instead of the tutorials, lets just get on with the test..you will see how everything works when we have found the problem.. I have traced the circuit down on your schematic and we are completed all the way to N3/1 grounding, so lets just do a few more test and a few more readings..
Did you get your meters ohm function to work yet ??

..or I can send you the schematic.

__________________
A Dalton

Arthur,

I read carefully your last post - and admit I do not understand 100% of it (most, but not all). So I will just report the facts, because I think they are showing exactly what you were predicting (but I will leave that conclusion to you):

I was not able to achieve 12 volts state again last night (by which I mean - after your post to try the wires in the relay - I continued to get 5 volts at 85/86.

Tonight with cold car - always 85/86 - key on/engine on:

1. Without relay in - 12 volts

2. With NEW relay in - still 12 volts - but pump clutch NOT engaging

3. I watched meter while allowing engine to run. At approximately 90 seconds after car was running, the meter dropped to 5 volts.

BECAUSE clutch did not engage during #2, I decided to verify load circuit.

4. I put OLD relay in (still coverless) - manually closed relay contact - clutch engaged.

*****

You had told me to verify NEW relay rating - I verified - it is 12 volts.

*****

I will await your next instructions.

Thanks!

P.S. I worked 13 hours today in the sun at the Ford car show. Some guy here is showing a MB (circa '66 sedan body style - with a 450 HP Ford motor in it - very weird!)

Jim

__________________
Syntax26

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

>


Hang Him !!!!!!


Ok .. if you are getting 12v at 85/86 and that relay is not pulling in, it looks to be the relay.




so, what I mean by verifying relay is :
...take the relay out and put 12v to those terminals [ 85/86] and see if you hear it click open/closed as you intermittantly put power to it's coil. ..use a couple of jumpers right off a 12v battery so we are not using any car circuits.

Does your ohm meter work yet???? that would really make this easier.

__________________
A Dalton