1982 model 250 w123- vacuum routing/carburetor diagram- HELP!

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blankenship

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hey all-
i own a 1982 model 250, a european model i'm having trouble finding ANY information about here in the States.
hoping this forum's the right place to come for help, because i know i'll have ongoing issues and am really looking for a place to learn + share.

she's got the 123.921 inline 6 cylinder gas motor and a Solex 4A1 carb, and the vacuum lines from the carburetor to the accelerator governor, fuel return valve, and distributor are all either missing or mis-routed. (i've made a post about it on a US forum here: http://www.schumanautomotive.com/forums/showthread.php?t=4367
) but am not having much luck resolving the issue.

hoping someone on this forum could pass along photos or diagrams or a description of the proper routing?
 
best i can tell

thanks for that link!
it's really tough for me to figure out what's going on in them, though...

maybe there's somebody whose got a better CONCEPTUAL understanding than i do, or someone who owns a similar vehicle could help decipher?

my 'givens':
1. i've got (2) ports that pull vacuum from the carb/throttle body:
one pulls vacuum all the time, and varies with RPM's.
one doesn't pull vacuum at idle, but begins pulling vacuum upon acceleration.
2. i have NO retard port on my distributor or and no vacuum ports on my fuel pump.
3. i have a 'thermovalve' mounted in the block whose ports are capped.

my best guess on vacuum routing is:
1. i connect idle governor to the carb port that pulls constant vacuum.
2. i connect the accellerator-actuated vacuum port on carb to the vacuum advance on the distributor.
3. i connect the top vac port on the fuel return valve to the accelerator pump suction port.
4. i connect the two bottom ports on the fuel return valve to each of the little ports on the bottom of the air cleaner housing.

what do you think?
 
yeah, i saw that. that's where i got my "best guess" from, but it seems the diagram's real purpose is to list parts, and without an understanding of how the system's supposed to work, i can't connect the dots...
 
books on the 250 are scarce, i got a brooklands manual for my 200... Is yours a M115 engine??
 
yeah, i've been having a REALLY hard time finding ANY info about the car here in the states...especially because it's NOT a 115 engine, but rather a 123 engine (who knew it wasn't just a chassis?:)) as far as i can tell, was used ONLY in this car (the 250)! mine's the 123.921 designation, which was used only from '79-'84...

some of the part descriptions DO tell you where they go, (which is the sole reason i've been able to put together that "best guess" on the routing), but there are so many 'exceptions' from year-to-year, and confusing/incomplete listings, and it's so different from current routing by the previous owner, that i just can't make any more sense of it...
 
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there cant be THAT many connections, and ive found that they dont have to be perfectly as set up from new, as long as there is a vac connection from manifold to anything that needs it, you are well on your way! It all follows common sense, figure out what the units do and you will figure out how they inter relate... sounds easier in theory i know!
 
yeah, i imagine there are only 8-12 connections or so, but even after reviewing the parts list + descriptions, i can't say with any certainty what's what. and i've got nothing to base it on as far as the vacuum routing i started with...

does ANYBODY out there on this forum own (or know anybody who owns) a '79-'84 model 250? anybody?
 
hmm.

yessir, i've considered ordering the haynes 250 book from the UK, but have waited because i've owned a LOT of haynes books in my life, and none of them have ever shown vacuum routing...

actually, i own this "Brooklands" w123 "workshop manual" already,
51CqEsrqvCL._AA240_.jpg

but it doesn't show or describe ANY of the vacuum stuff :(




i'm sure hoping to find someone who'll take a couple photos under their 250 hood that would solve everything in a minute :)
 
How about this one? Says it includes vacuum diagrams for the 280. Remember also that pictures of UK cars may not help in that the european models may differ from their USA counterparts because of extra emission equipment? Dont know this for sure but worth considering if anyone posts some pics ?
 
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No Go

well, i bought BOTH the Haynes and Chilton books, and NEITHER have vacuum diagrams for my 250. they show a good deal of emissions controls for the fuel-injected version, but it's totally and completely different.

i'm still very confused about the routing of this fuel/vacuum stuff, and nobody i've reached out to seems familiar. :(
i've tried to educate myself about it, and have routed the hoses to my BEST guess, but the car still shows major symptoms that what i've done is incorrect.

so, i'd really appreciate it if somebody's got photos or diagrams of the routing on their 250, (or even from their 280 model, which should be fairly similar)!
 
i wish you were closer, we could sort this out within a couple of hours but without looking at it, its impossible...
 
As well as the page television has posted look HERE.

Look at the intake and exhaust manifold sections and the engine electrical section for the distributor.
 
what if ?

any chance of having input from you guys based on all the postings, photos, and drawings i've posted HERE ?

i did have a look last month at the manifold and electrical parts diagrams from the detali.ru site, and they're what led me to route the stuff as described HERE, in the last page of the thread posted above...
(which routing ain't working for me :(
 
From the stumbling description it sounds like you might have an air leak into the manifold, maybe the carburettor base gasket..

Spray brake cleaner round all the joints and pipes at idle and see if there is any difference in the running or smoke output. If so you've found the leak.

I would be surprised if any of the carburettor add-ons are playing any particular role at part throttle, normally they come in for full throttle conditions.

It could be running lean at idle so has had the mixture strength increased, which then causes too rich a mixture at part throttle. This then clears at full throttle.

If you connect a vacuum gauge you may find very low vacuum.
 
Some of these pipes can be checked, for instance with a timing light you could check the advance mode by removing the pipe, and watching the strobe lamp
 

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