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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #1
Hi folks
My Euro 1989 230TE wagon started and ran well all winter.
Now that the weather is warming up in France, the does takes a few seconds of cranking to stat and has a flat spot driven under 50kph (30mph)
So here goes again with that dreaded KE jet fuel injection...

In fact it takes a lot of cranking to start the engine once warm and it stalls easily at idle (about 550 rpm)

Tips ?

Denis in Covid19 infected France
 

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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #3
You could be right here ...I will look into this despite the fact that most ignition parts have less than 2000 miles.... Could it be fouled plugs from short winter trips ?

Denis
 

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W124
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If your distributor is similar to that on an M103 make sure you also change the insulator (Mercedes calls it a dust shield) behind the rotor mount.
 

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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #5
Today the weather is colder and the car runs flawlessly !!!
So I dont think ignition is the problem but denser air makes for a richer mixture.

Could it be that the car runs too lean ??

Or maybe the engine had a coronavirus and is well again ...

Denis
 

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W124
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Most fuel problems are caused by ignition. I wouldn't be overthinking the mixture issue at this point. When you say "most ignition components have only 2000 miles on them", which are new and which are not? (wires, cap, rotor, plugs, insulator?
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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Also don't overlook the voltage regulator. If its never been replaced, just do so because a worn voltage regulator will undercharge the battery and not give the electronics enough juice to keep it running smoothly especially at low revs.

I've come across quite a few Ke-Jetronic cars with long crank or crank/briefly run and immediately die all due to the voltage regulator.

Also your idle is too low, it should be around 700. Probably even slightly higher for the little 4 cylinder engines. But this too can be caused by a bad voltage regulator. It is the cheapest part you can throw at it before delving into ignition and fuel systems.
 

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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #8
Voltage regulator is new, and frankly how do you explain PERFECT operation (cold-warm-normal temp) over 25km with something "defective" with an ignition component ? It simply doesn't add up IMHO.
No time or inclination to look into this with the heavy confinement policies going on in France...
Denis
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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...stalls easily at idle (about 550 rpm)
550rpm at idle is far from PERFECT operation. 6 Cylinders need to be around 700rpm, so your little 4 cylinder is probably going to be happier turning at least 750-850rpm but less than 1000rpm.

What is the condition of your EHA? Ever been replaced or leaked?
 

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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #10
EHA, yeah cleaned, replaced and cleaned again... I guess all these KE jet POS parts need regular cleaning like every six months... wish the car had a plain carburettor which are way easier to tune than the (over)complicated KE jetronic stuff. This old, obsolete system is too complex with interdependent parts to keep adjusted like an old plain K jet was...

550rpm is whet the tach reads, not a real measurement but the M102 I have is in very good shape and smooth like a six...

Thanks for the tips...

Denis
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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If you're doubting the idle speed shown by your tach, then verify your actual idle speed with a half decent digital timing light that has a integrated tach function like this one.

I think the low rpm is the key giveaway that all is not well.

And no matter how you slice or dice it, a 4 cylinder will never be as refined as a 6 cylinder. Yes, the M102 is better than most even its successor the M111 BUT still can't hold a candle to the smoothness of a properly running 6, 8 or 12 cylinder. Just not gonna happen.


And while you may "wish" for a carb'd W124, try keeping a W124 200 with the factory Pierburg in tune. While I am no lover of the Ke-Jetronic system, I'll take the KE-Jetronic over the carb version any day of the year. Fuel bowls, floats, jetting, speed screws . . . who needs that misery.
 

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W124
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EHA, yeah cleaned, replaced and cleaned again... I guess all these KE jet POS parts need regular cleaning like every six months... wish the car had a plain carburettor which are way easier to tune than the (over)complicated KE jetronic stuff. This old, obsolete system is too complex with interdependent parts to keep adjusted like an old plain K jet was...

550rpm is whet the tach reads, not a real measurement but the M102 I have is in very good shape and smooth like a six...

Thanks for the tips...

Denis
Denis,
You are right. These cars are now so old that it can be very difficult and expensive to get the fuel injection and the engine working correctly again. I would love to see a two carb manifold for these cars.

Andy
 

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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #14
The M102 230 on W123s had a single stromberg carb. Not much power but THAT is what I call simple...
For an M103, never had carbs but does it make sense to put a custom twin carb manifold on an engine with such limited potential , I also mean financial sense... plus it becomes agaz guzzler...

The other problem is that at least in Europe, the youngtimer fad means that any pre-1990 car is "collectible" and worth lotsa cash, which is, IMHO crazy.

Denis
 

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If you're really stuck on going the carb route, then this might be the way to go. Of course, nothing comes cheap.

 

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W124
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The M102 230 on W123s had a single stromberg carb. Not much power but THAT is what I call simple...
For an M103, never had carbs but does it make sense to put a custom twin carb manifold on an engine with such limited potential , I also mean financial sense... plus it becomes agaz guzzler...

The other problem is that at least in Europe, the youngtimer fad means that any pre-1990 car is "collectible" and worth lotsa cash, which is, IMHO crazy.

Denis
I get it. I am sure some guys who fabricate manifolds for race cars could fab one up pretty quickly but sure it would cost a pretty penny. A downdraft holley carb 4bbl carb would be simple enough and provide plenty of fuel when needed. But yes, it wouldn't be thrifty. Maybe a more up to date electronic fuel injection set up would be a better choice and a more popular distributor with mechanical advance to replace the original design. Without doing anything really drastic (bottom end) maybe 225hp could be made. Granted that's a lot of work but then again, no more EHA, EZL, injector seals, fuel distributor, lambda issues. :)
 

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1990 Benz 300E 2.6 (mine) ; 1994 E320 Wagon (wife's) ; 1993 300CE Cabrio, needs some TLC
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i'd rather have a pair of constant velocity aka side draft strombergs or SU or whatever, sized appropriately. those have a very linear throttle response and don't need accelerator pumps.

but there's no way any sort of carbs would come close to the efficiency of any sort of FI. either you'd have less low end torque, or less high end power, or less fuel economy.
 

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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #18
I completely agree and remember that once I understood how the SUs on my dad's '66 Volvo worked, I spent twenty minutes every fall and spring and that was all. The car was super reliable.
One must remember that Skinner's Unions (known as SUs) were fitted to Rolls Royce cars back in 1908. IMHO, such variable venturi carbs are what great engineering is all about.

The problem is that fuel injection with sensors and computers DO NOT age well. Parts cost and availability can be dreadful and this is what is happening on KE jetronic systems, as far as I know, later systems are even worse...

Denis
 

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I'm familiar with SUs too and their little brothers - Amals (used on Brit bikes). Topping up the oil damper was about all I remember doing after synching them up. I think the Strombergs, with their diaphragm, was a better idea than the SU. As the bores scored or wore (on the SUs), the effectiveness of those carbs suffered.

Had a set on a Big Healey back in the early 80s and if I got a lean mixture "pop" back through the intake it would send the SU pistons slamming up in the bore until one day the poor little shaft the damper was mounted to broke through the plastic cap you use to loosen and remove them. A new set of dampers and a little richer mixture solved the problem.

But for sure Leftcoastgeek, the acceleration was smooth with those carbs.
 

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S124 a 1989 W124 230TE originally from Germany
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Discussion Starter #20
Big Healeys in the sixties ? Knew a poor fellow who bought a new one only to fing that the paint was peeling off after six months !! Those years were the decline and crash of the UK auto industry somewhat before the USA went a similar route...

I has a Volvo 245 with a single stromberg - cleaned out and adjusted the carb ONCE and it ran very well...way better than my "computerised" KE jet Mercedes S124 !

Denis
 
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