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Any KE-Jetronic Experts In The UK? M103 W124 (or EFI/Turbo?)

DanMorgan

Active Member
Joined
Mar 7, 2012
Messages
760
Location
Cardiff
Car
R129 500SL, W124 300CE Twin Turbo, W210 E55 AMG, W211 E320 CDI Sport
Hey,

I want to get my W124 300CE mechanically sound and futureproofed.

Currently, the car in question has 31K miles and it would be great to have the KE-JET sorted to keep everything original (I even have a mosselman twin turbo kit in a box to go on it too).

However, part of me thinks it would be easier and cheaper just to do a full EFI conversion and a turbo?

Therefore, two questions.

1) Are there any garages in the UK that are dedicated to solving M103 KE-JET issues?
2) What Full EFI/Turbo kits do you recommend

Cheers for any information!
 
hi
looking for an expert on KE systems myself, air flow plate is sitting low and running rich but no adjustment on the grub screw, needs the plate re-setting...
 
Personally if it’s an original 31k miler I wouldn’t be messing around with turbo kits or aftermarket stuff.

The 300CE is an appreciating old classic, not sure it’s worth ‘tuning’ stuff like these nowadays but each to their own I guess.

Maybe if you’re considering that route a 24v car with EFI to begin with would be a more suitable base car?

If you just want to get it up to A1 condition there’s plenty of specialists out there who can recondition, test and calibrate the various parts of the fuelling system. Mostly it will be age related stuff like seals, gaskets, deposits from old fuel etc. It’s not that complicated really - refurb the fuel distributor, check the fuel pumps are working okay, ensure the electronic sensors are performing as they should. Injectors are cheap to replace if needed etc. Loads of info out there on forums and parts availability is pretty good from what I can recall :cool:

Just try and avoid ethanol in fuel as much as you can, the old fuel system doesn’t seem to like it.
 
Personally if it’s an original 31k miler I wouldn’t be messing around with turbo kits or aftermarket stuff.

The 300CE is an appreciating old classic, not sure it’s worth ‘tuning’ stuff like these nowadays but each to their own I guess.

Maybe if you’re considering that route a 24v car with EFI to begin with would be a more suitable base car?

If you just want to get it up to A1 condition there’s plenty of specialists out there who can recondition, test and calibrate the various parts of the fuelling system. Mostly it will be age related stuff like seals, gaskets, deposits from old fuel etc. It’s not that complicated really - refurb the fuel distributor, check the fuel pumps are working okay, ensure the electronic sensors are performing as they should. Injectors are cheap to replace if needed etc. Loads of info out there on forums and parts availability is pretty good from what I can recall :cool:

Just try and avoid ethanol in fuel as much as you can, the old fuel system doesn’t seem to like it.
hi - are you aware of anyone reconditioning KE air flow sensors at all?
 
hi - are you aware of anyone reconditioning KE air flow sensors at all?
You can replace the potentiometer if needed, if there’s much else wrong I would just grab a used one - still plenty of these sorts of parts out there.
 
Personally if it’s an original 31k miler I wouldn’t be messing around with turbo kits or aftermarket stuff.

The 300CE is an appreciating old classic, not sure it’s worth ‘tuning’ stuff like these nowadays but each to their own I guess.

Maybe if you’re considering that route a 24v car with EFI to begin with would be a more suitable base car?

If you just want to get it up to A1 condition there’s plenty of specialists out there who can recondition, test and calibrate the various parts of the fuelling system. Mostly it will be age related stuff like seals, gaskets, deposits from old fuel etc. It’s not that complicated really - refurb the fuel distributor, check the fuel pumps are working okay, ensure the electronic sensors are performing as they should. Injectors are cheap to replace if needed etc. Loads of info out there on forums and parts availability is pretty good from what I can recall :cool:

Just try and avoid ethanol in fuel as much as you can, the old fuel system doesn’t seem to like it.
Indeed - That's my issue and why I would want to keep the engine original where possible. The car itself has a full AMG body kit, AMG suspension, AMG MOMO steering wheel, exhaust and monoblocks but everything else is stock.

Regarding the turbo - the mosselman twin turbo kit was an option back in the day and came from another W124 coupe.

I have since been talking with a local company who are indeed K-Jet Specialists and right on my doorstep (very lucky!) and in talks to get the car booked in.

For reference, this is the company -> K Jet Specialists in South Wales – Got Boost
 
Indeed - That's my issue and why I would want to keep the engine original where possible. The car itself has a full AMG body kit, AMG suspension, AMG MOMO steering wheel, exhaust and monoblocks but everything else is stock.

Regarding the turbo - the mosselman twin turbo kit was an option back in the day and came from another W124 coupe.

I have since been talking with a local company who are indeed K-Jet Specialists and right on my doorstep (very lucky!) and in talks to get the car booked in.

For reference, this is the company -> K Jet Specialists in South Wales – Got Boost
They sound like a great find :)

My only comment regarding the originality/tuning side of things is that I don’t believe this fuelling system is all that good with forced induction. If you’re doing away with originality and fitting turbos I don’t see the issue with upgrading the fuelling side of things to EFI and having it running properly and reliable :cool:

IMHO these 80s turbo kits were never that good, I would focus on getting the car to A1 standard and keep it as it is, and would use another base car to modify but that’s only me, no right or wrong really 👍
 
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As Will says these engines took a lot of fettling to stay in tune even when new. A major problem was under bonnet heat as witnessed by the heat exchanger just above the injection system inlet in the video. Many bonnets had louvres cut into them to reduce the underbonnet temperature as I recall.
 
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You can replace the potentiometer if needed, if there’s much else wrong I would just grab a used one - still plenty of these sorts of parts out there.
worried s/h one will be as worn as mine and need adjusting up anyway though, plate is low and adjuster won't go any higher...
 
worried s/h one will be as worn as mine and need adjusting up anyway though, plate is low and adjuster won't go any higher...

You can check the condition before installing though. Worst case you’ve got a good set of spare parts and a unit that you can fit a new potentiometer too whilst keeping your old one intact 👍
 
They sound like a great find :)

My only comment regarding the originality/tuning side of things is that I don’t believe this fuelling system is all that good with forced induction. If you’re doing away with originality and fitting turbos I don’t see the issue with upgrading the fuelling side of things to EFI and having it running properly and reliable :cool:

IMHO these 80s turbo kits were never that good, I would focus on getting the car to A1 standard and keep it as it is, and would use another base car to modify but that’s only me, no right or wrong really 👍
I'll see what they think about it - I am going to take all the bits in the boot and show them the official installation guide (attached if anyone is interested).

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As Will says these engines took a lot of fettling to stay in tune even when new. A major problem was under bonnet heat as witnessed by the heat exchanger just above the injection system inlet in the video. Many bonnets had louvres cut into them to reduce the underbonnet temperature as I recall.


Believe it or not - the kit came from the exact same year (1987) 300CE as mine with 220K miles on it! The plan was to fully refurb the kit before putting it onto mine.

However, I am still in two minds about whether or not to just sell the kit and just run the car as standard. After all, I have many other performance-based cars (i.e. keep the 300CE as a cruiser)
 

Attachments

KE is simple, if you go with EFI, you'll have to adapt the fuel rail and possibly the intake to support it or use one from a later car.
 
Just to keep this updated - I am going down the EFI & Mosselman Twin Turbo route (will have a modified intercooler).

I have been offered a Dogleg from a Cosworth, for the conversion to happen, what do I require:

  1. Dogleg gearbox
  2. Dogleg gear linkage
  3. Flywheel
  4. Gear shift
  5. Gearknob
  6. Pedal box

Will I also need the propshaft?

TIA
 
Just to keep this updated - I am going down the EFI & Mosselman Twin Turbo route (will have a modified intercooler).

I have been offered a Dogleg from a Cosworth, for the conversion to happen, what do I require:

  1. Dogleg gearbox
  2. Dogleg gear linkage
  3. Flywheel
  4. Gear shift
  5. Gearknob
  6. Pedal box

Will I also need the propshaft?

TIA

As your dogleg box came from a cosworth it should be the long input shaft version, so you need the older solid flywheel to match. I'm assuming your going to bin the EZL and dizzy and run 6x coils? If you are it wont matter if the flywheel is for a 4 or 6cyl engine, if your keeping the EZL setup you need the proper M103 flywheel.

The gearlever assembly itself is different for a dogleg box, though the 3x linkage rods are the same for any manual w124. The pedal box can come from a 190, w124, w202, and I think w208.

The front section of the propshaft is longer on a manual w124, you will struggle to find that as there are 3 different versions. The front section from a w210 can be made to work in it's place.

The part that everybody forgets is the clutch fluid feed line from the brake reservoir to the clutch master cylinder, it has a plastic push in fitting that can be a pain to get right.

You may need to think about a diff upgrade to a 210mm version, the small diff the 300e has wont last long. That use's shorter drive shafts, but a longer propshaft.
 
However, part of me thinks it would be easier and cheaper just to do a full EFI conversion and a turbo?

That must be the crazy part then? $millions went into developing the system in your car and there are parts catalogs available that will tell you all the part #'s so you can order replacements and well documented instructions on how to fix that system.

Do you really think that you have a friend that can do it cheaper?
 

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