Trigger Point Conundrum

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cjhols
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Model you own: w107
Location: Bendigo Australia

Trigger Point Conundrum

Post by cjhols » Tue 15 May, 2018 6:05 pm

Hmmm
As pointed out in a previous post I inadvertently unhooked the trigger point connector ( It fell apart -see photo) and in my stupidity may have hooked it up the wrong way. I have simply hooked corresponding colour to corresponding colour (except for the Yellow/blue wire which only has a yellow wire from the distributor - NOT the expected blue).
IMG_0620.png

Anyway, whilst the engine coughed and spluttered for a little while now it won't fire at all.
I'm wondering whether I may have damaged something by mucking around (trying different sequences of connections) ? For eg: a fuse, coil, points or something more sinister.
Can anyone please suggest a 'check list'
of diagnosis so that I might cure this conundrum.
Thank you
Peter
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1973 SLC 450
1971 Clubman Mini

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Mercmad
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Model you own: w109
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Re: Trigger Point Conundrum

Post by Mercmad » Thu 17 May, 2018 1:53 pm

The trigger points dont have a condensor . Unless someone has connected a radio supressor. The only thing that will stop an engine like you describe is Fuel. Are you sure you are getting fuel delivery (28 PSi ) at the cold start valve? Here is the most comprehensive check list you will ever find for sorting out Djet. Go through everything until you get the car running and do it it in the order he lays out. https://oldtimer.tips/en/

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cjhols
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Posts: 122
Joined: Sun 31 Mar, 2013 10:06 am
Model you own: w107
Location: Bendigo Australia

Re: Trigger Point Conundrum

Post by cjhols » Thu 17 May, 2018 6:34 pm

Hi,
I might have just figured out the problem. Correct me if I'm wrong but it appears that someone has wired the trigger points up with the wrong order of
IMG_0630.JPG
colours - Which means when I was trying to connect the wires from the ECU (Matching colour to colour) they would in fact NOT match. Could you please check the photo and see what you think???
Regards
Peter
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1973 SLC 450
1971 Clubman Mini

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Mercmad
Mercedes Demigod
Posts: 8053
Joined: Sun 11 Sep, 2005 8:01 pm
Model you own: w109
Location: Brissy
Contact:

Re: Trigger Point Conundrum

Post by Mercmad » Fri 18 May, 2018 6:58 am

I Have never seen them with coloured wires, normally they are just connected with white wires(some were printed with numbers), But i have had to resolder plenty over the years. If you check Dr Djets pages you will find which terminal in the points set connects to the corresponding number on the plug .Then you check from from the ECU plug,which is also numbered ,to the points for continuity. When fitted, there should be one set open and one set closed. He also has lots of good nfo on the best way to fit the points to avoid damaging them,which is something you never want to do as they are no longer available from Bosch or Mercedes and even cheap copies cost $400.

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cjhols
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Posts: 122
Joined: Sun 31 Mar, 2013 10:06 am
Model you own: w107
Location: Bendigo Australia

Re: Trigger Point Conundrum

Post by cjhols » Wed 08 Aug, 2018 5:36 pm

Hallelujah,
After a seeming eternity I found the fault. Nothing wrong with the ECU or TPS or the TP. Two wires at the base of the joining connector (ECU and T/P) had frayed to the point that they were just holding on. I re-soldered and away it went. Well 7 of the 8. In the process I found that Injector 1, whilst receiving a pulse and having the correct resistance must be stuck - I will work on that next. But a big thank you to all of you. It goes to show how such a small thing can cause such a headache.
Signing off ( for a little while at least )
Peter
Thank you
1973 SLC 450
1971 Clubman Mini

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