__________________
1987 W201 190D
>

....and what do you think the X27 connection terminal does ???

__________________
A Dalton

I think it adds another uncertainty to the procedure, as you said:
Otherwise I think it's fine. Obviously easier, and if it cranks by jumping it there then there's no point in going to my suggestion.

__________________
1987 W201 190D

whenever i have a starting problem i suspect fuel delivery, ignition and the starting circuit and elimnate anything that is fine. Check the obivous like fuses etc.

Just because the fuel pump can be heard working doesnt mean the system is up to pressure. I would take a quick fuel pressure test to verify if its working or not.

I would pull a spark plug and see how they look and inspect the ignition system. Also make sure the timing is right.

If these all checked out then I would starting elimnating components in thestarting circuit by making sure i have a good battery, do a few tests with a dvom to check the wiring, make sure the NSS is doing its job and then I would be left with the starter(ignition switch would be elimnated after 12volts was reaching the starter)

Kinda hard to diagnosis problems if you dont have the car in front of you

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

Correct ... and that is why they put it there ...cuz you can't get to the wires at the starter on a 124.032 chassis car.
But you have a valid point and that is the old way we did it on an open engined compartment car/truck.
If you read his post, you will see that he has already done his homework and read one of the circuit tutorials I have in the Archieves on this exact chassis procedure ,,,that is how he knew about the X27 shortcut we use for diagnosis on this particular chassis.
The other VERY COMMON failure part on this exact chassis is they had a problem with the harness that went from the X27 test connector to the starter solinoid b/c of bio-degradable wire insulation...so, knowing that, one can see why my next recommendation step is to check that harness for that common complaint before changing the starter...he understands where the diagnostic stand and I credit him for using the Search feature of the Forum.
We are on the same page..and I am aware of this chassis circuity and it's common failures and weaknesses.............

__________________
A Dalton

If these all checked out then I would starting elimnating components in thestarting circuit>

He has a NO CRANK condition.... I would certainly not be checking the timing and ignition system before I got the car to Crank....

Are we reading the same post??????????? Did you see his answers ????

its off topic yes so it obivously doesnt fit this situation.....................

And btw your suggestions for the stalling problem i had a while ago with the 190E didnt solve the problem, paided a dealer foreman nd he didnt solve the problem and I found the problem and I dont have any manufacturing training ether or years of experience....

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

Yes, we are on the same page. I am not aware of the peculiarities of this chassis, which is why I asked in an early post in the thread if the starter was reasonably accessible. I did not get a response to that question, so I offered a very simple and 100% unambiguous diagnostic procedure. Unfortunately it seems not to be practical in this particular car.

__________________
1987 W201 190D

Very Good.
I was answering your post by mentioning the X27 test connection.
And he knew of it from the Archieves , so There was no reason to explain it in detail. as the thread was a diagnosis for his complaint. But , either way..we have a starter or starter feed problem and we both understand that, as well as he does. ..

__________________
A Dalton

__________________
>

I remember when you first started posting as a 'Techinician".... [ I believe that's how you spelled it ?]...so why did you even have to ask ???????????

__________________
A Dalton

A former tech moving on from it actually but why I posted is I got a bit impatient like we all do and wanted a quick answer but should of know better.

Calmed down and fixed the problem which I paid a MB dealer foreman to fix and he didnt since the problem only came back. I didnt bother bringing the car back to him after I saw what he did to the car.

Anytime I get a car to fix with a problem whether its friend, family etc its fixed right the first time and its work I can be actually proud of. I dont know how a MB dealer foreman coulda thought doing what he did to try solve the stallling problem worthy of charging someone.

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

i agree with slk230red, the starter lockout switch, assuming this is an automatic. keeps you, as a supposed idiot user, from starting the car in gear. i have had the same thing happen.

I finally got a chance to take another look tonight after work (still light out thanks to time change). You were right Arthur, the wiring harness insulation from x27 to starter is almost completely gone....dust. And the x27 wires run right beside the oil filter....and I guess I didn't mention in my first post that I had an oil change before the emissions inspection. And it looks like fresh wiring insulation dust has been deposited from oil filter manipulation in that area. I'm thinking/hoping now that my no crank condition is the harness rather than the starter/solenoid? Nevertheless, the harness needs to be replaced so I guess that is my next step. There are 3 wires from the x27 switch running down towards starter. It looks like one goes down to the starter/solenoid. Anyone know where the other 2 go? And I suppose this harness is going to be a dealer only part?

Yeah, I kinda figured that , as that was a common prob with that chassis..

The other 2 wires on X27 are oil pressure sw and level. OP is terminal #1 [bk/gn ] and OL is term# 3 [bn/bk ]

Anyway, no way around it except you could run a single wire from X27 center terminal to starter solinoid and then cut the old one off at both ends just to get you back to a normal Start/Crank condition..then order the harness and do it . If you do chose to do that, you can also test the starter/sol by bringing 12v bat + to the new wire just like you did when you used X27 as the test point.
There is a tutorial in the Archieves on that replacement job...might even be in the DIYer section.
The oil filter change is what finally did it in...same happens to the engine harness when they change spark plugs...as soon as they get disturbed , they fall apart..literally.

__________________
A Dalton

I'm happy to announce....it's running!! Turned out it was the starter after all, even though wiring from x27 to solenoid/oil press/oil level was almost completely void of insulation. I ended up re-insulating wiring with electrical tape (dealer wanted $140 for new). Got rebuilt Bosch starter for $180 and just now finished install.

Also replaced spark plugs, since I still have to pass emissions inspection after I failed 2 weeks ago (high hydrocarbons). Old plugs were really worn down (electrode tip) and gap was more than double spec. I hope this will be enough to get it to pass tomorrow...... If not, I will be back asking for suggestions.

Thanks all for your help, especially you Arthur, this is really an amazing place!

Brad

Very Good.

And you now know the value of using the X27 connector as a test point for diagnosis of the system...Many do not realize that once you jumper to X27, you have literally eliminated the NSS, Ign sw, K38 relay , and ATA system b/c you have by-passed all these circuits in the Cabin...That is why X27 is the preferred test point. [ it is a mid-point circuit seperation of cabin controls and under hood components]
Another plus of this knowledge is that if anyone does get into a no crank condition b/c of any of those upsteam failure conditions [ which are very common] they can simply use that X27 jumper trick to get the hell home......

__________________
A Dalton