Mercedes W114 250 Coupe - help!

[Charles Morgan]

It's always very helpful to have a good old debate on this stuff. Much as I hate to say, money is becoming an issue on this and something plug and play is important, for that, and if I'm very honest, because my brain is currently hurting and I just want to get the thing on the road now, with the minimum of fuss.

Noted about the dizzy looks, it wouldn't be the end of the world,

 

[grober]

A MEGASQUIRT PRIMER
Following on from the M110 Megasquirt write up 280SL "K-Jet and Ignition conversion to Megasquirt" write up - Mercedes-Benz Forum

I found this visual explanation of the various types of Megasquirt board and processor helpful.
If you buy a used MegaSquirt

and this manual as to how you would set up 2x3 injector blocks for a 6 cylinder
and the electronics required for a 3xtwin coil wasted spark ignition.

http://www.msextra.com/doc/pdf/MS2V30_Hardware-3.3.pdf

 

[Bellow]

A MEGASQUIRT PRIMER
Following on from the M110 Megasquirt write up 280SL "K-Jet and Ignition conversion to Megasquirt" write up - Mercedes-Benz Forum

From the above, post#10:

''Ignition

If one only wants to replace the ignition system, its a little overkill to use MegaSquirt since it’s mainly made for controlling the fuel injection and the ignition control come as a bonus. There are many 3’rd party dedicated ignition systems which do exactly what my setup does probably for a better price if one only want to modernize the ignition system ''


Post#11 re setting up MS for ignition:

''As usual I did it the easy way, I measured my ignition curve using a stroboscope lamp before switching the ignition and used that to create a decent ignition map which works very well in my opinion (see picture) there are certainly more to be done on it but it works very well as it is.

I mesured:
10 deg / at Idle (800rpm)
28 deg / 1500rpm
44 deg / 4500rpm
Since it's possible to fine tune the fuel and ignition those values are very ruff but work as a start map.''

and from the opening post:

''Picture 3 shows the standard MS installation where the trigger signal for injectors is taken from the ignition coil, best choise if only replacing the fuel system .

Picture 4 shows the standard MS installation where the trigger signal for injectors is taken from a toothed wheel which is mandatory if one want to control the ignition.''

 

[Charles Morgan]

Lots to read when I have my big May concert out of the way this weekend.

The metal polishing kit arrived yesterday so I did a test panel of my ally cam cover. I think it needs a bit of a sand first to get rid of the scratches, but I think it will come up well, after a lot of work...

 

[guydewdney]

There is a possibility i have a m110 dizzy complete in my garage. I know its a dizzy, just off what is a different matter

 

[Charles Morgan]

Cheers Guy, but the 123 is the way ahead for the car on the dizzy front.

 

[grober]

In case you wanted to go the Petronix route [ FUNDS??] then this is an excellent thread.
PerTronix (Hall Effect) Ignition for Mercedes-Benz Pontons © www.mbzponton.org
The unit required is evidently the 1867A which fits the Bosch 231187001 JFU6 distributor [W114-250]
http://www.amazon.com/dp/B000N2ZG4U/

QUOTE :-
My name is Bob Altenhoff and I live in British Columbia, Canada. My cars are a 1960 Mercedes-Benz Type 180Db Ponton diesel and a 1958 Type 219 Ponton sedan. The Type 219 has a Bosch distributor # 231187001 (JFU6) which was also used in the 1968-1970 W114 250 and 280 models (Len Sokoloff can confirm this). This distributor was also used as an upgrade in the Type W180 220a and W105 Type 219 Ponton 6 cylinder models (Niemoeller in Mannheim, Germany sells them for € 540). I found out from PerTronix tech support that the PerTronix 1867A igniter module fits this type of distributor. I installed the unit in less than twenty minutes. Everything fit; no modifications, grinding, Loctite or silicone was required. The only thing I did was adjust the gap between the pick up coil and the magnet to 0.030 inch with the plastic gauge which was provided in the kit. Otherwise, it fit like a glove. I also installed a 40,000 volt coil with a built in 1.5 ohm resistor, but this was totally optional as it would have run fine with the regular Bosch coil. I must say I am very impressed with the way the car performs now. Also the 1867A PerTronix Ignitor kit sells for $14 less than the 1864A used in the older distributors. I can provide photos if anybody is interested.

 

[Bellow]

Dizzy is corroded and not serviceable.

In light of G's post...
Only the advance and retard mechanisms need to be functioning. Is there any possibility they can be freed? (Weep unicorn, weep).

 

[Charles Morgan]

Very interesting! I'll bring in the old dizzy and have a look, of one thing I am certain, the unicorn tears have been pretty miraculous so far!

 

[grober]

It's a horses for courses thing really. While the petronix set up is a budget alternative to the 123 distributor which weighs in at a considerable £260 the worst thing about old distributors is shaft/bearing wear allowing that centre shaft to flap around- which can lead to erratic timing- if you also factor in the possible cost of a decent new distributor cap and rotor arm to bring it back to spec then that price differential starts to slip a bit . Southern Carburettors seem to be the UK agents for both Petronix and 123---
=http://www.sciperformance.co.uk/pa...ncluding the increasingly popular 123ignition
The 123/MERC6-R-V-IE appears to be the one for injection cars which may have a slightly different advance curve??
As always in restorations when deciding how to proceed actions have to mitigated by available funds but also by a detailed assessment of the state of the existing hardware you have to work with. Sometimes it will pay to spend a bit more money on essential items like ignition particularly if you are going to use it for injection timing also?

 

[Bellow]

G: As far as I can make out the Petronix part is merely a triggerring unit - a timing (advance/retard) mechanism is still required. However, that may be recoverable in the car's existing dizzy and if the main shaft isn't so worn as to upset hall effect sensor (less sensitive than points? - geometry) then entirely plausible to use it (with the addition of Petronix). In any case, unless fully sequential injection is sought the timing will not be crucial, the dizzy providing rpm indication and not much more.

What I'd look for in the existing dizzy (assuming it can be freed off) is no excessive wear in the mainshaft or advance/retard mechanism pivots (though some reclamation via oversized pins or rebushing may be feasible); that the springs aren't stretched (or are available as replacements); that the vacuum capsule isn't leaking (or can be replaced); and that the drive gear isn't pitted through its wear surface. The last in the list is potentially the worst scenario.

 

[grober]

G: As far as I can make out the Petronix part is merely a triggerring unit - a timing (advance/retard) mechanism is still required. However, that may be recoverable in the car's existing dizzy and if the main shaft isn't so worn as to upset hall effect sensor (less sensitive than points? - geometry) then entirely plausible to use it (with the addition of Petronix). In any case, unless fully sequential injection is sought the timing will not be crucial, the dizzy providing rpm indication and not much more.

What I'd look for in the existing dizzy (assuming it can be freed off) is no excessive wear in the mainshaft or advance/retard mechanism pivots (though some reclamation via oversized pins or rebushing may be feasible); that the springs aren't stretched (or are available as replacements); that the vacuum capsule isn't leaking (or can be replaced); and that the drive gear isn't pitted through its wear surface. The last in the list is potentially the worst scenario.

Wouldn't disagree - that's a good summary of all the potential mechanical issues ---not forgeting the electrical insulation+contacts /state of the cap and rotor arm that need to be checked on the old distributor before deciding if a Petronix upgrading+reconditioning is the way to go V total replacement.

ps one phenomenon I have frequently come across in older cars [ usually proportional to age ] is what I would term "non equivalent substitution" Its where certain items have been substituted by "near equivalents" [ second hand] rather than "exact equivalents " by less than fastidious previous owners usually due to lack of supply or funding. Sort of example might be where a distributor that " fits and functions" after a fashion has been substituted for the correct part which has failed . Might only differ in its advance mechanism and the car appears to run fine-- but is down on performance slightly. Just sayin ---another pitfall to watch out for.

 

[Bellow]

I am assuming a cap and rotor arm are available off the shelf as comsumables...

Re it being the part the car left the factory with - absolutely correct and for some things one can but hope! However, the hope for me is that MB built their cars robustly enough for components not to have failed so early as require replacement. That and part number cross referencing....

 

[Charles Morgan]

Just had a look at the dizzy. The arm moves freely but with a very superior action, no looseness at all, just a nice engineered rigidity. The rest of it is a bit manky having had no cap on for some considerable time. New rotors and caps are available. I think it refurbish able, but I worry that in that process I will render it useless.

 

[Bellow]

. I think it refurbish able, but I worry that in that process I will render it useless.

Me too; you wont; but if you are feeling a touch squeamish and are prepared to trust me with it - post it to me and I'll give it my all to resuscitate the critter.

 

[Charles Morgan]

That's an exceptionally kind offer Bellow and very much appreciated, it feels such good quality I am certain that someone who is more capable than I can get it going, in which case the Petronix option becomes a real goer.

 

[grober]

Is there a part number on it anywhere? If you remove the semicircular plate with the black electrical connection held in by the two screws lower down the body you should also be able to examine the two contacts breaker/points assemblies for the D Jetronic injection - each one firing a bank of 3 injectors
http://www.mbclub.co.uk/forums/2092000-post7.html

 

[Charles Morgan]

The only numbers are PEUR6 and 0231301004. I wonder if this is the later dizzy replacing the Pertronix compatible one you mentioned earlier.

I shall clean it all up tomorrow and have a little peek at the D jet just for you Graeme!

 

[grober]

The only numbers are PEUR6 and 0231301004. I wonder if this is the later dizzy replacing the Pertronix compatible one you mentioned earlier.

I shall clean it all up tomorrow and have a little peek at the D jet just for you Graeme!

Thats the one! may be PFUR6 but 0231301004 is the one.

 

[Charles Morgan]

PFUR it is.