M116 won't start

[BenzBoy]

Ok guys it is the fuel metering/distributor unit, how do I know you ask? Well fitted new plugs totally dried out the cylinder bores and the entire intake system took ages!!!!!!!!!!!!!!

So then I pulled the fuel pump relay and whilst young Harry took great joy in turning the engine over to start, I opened the throttle wide up and poured 40mls of fuel down the opening. Presto engine spluttered straight away I repeated three times and he is burning the fuel straight away.

So despite having excellent fuel pressure and flow at the injectors it would appear something in the meter or distributor has called it quits leading to substantial flooding. Hence the no starting issue and it would explain the excessive black smoke at start up I was getting before the whole thing died. So the search is on, for an entire fuel assembly not cheap!!!!

Lesson learned people, despite what some think a W126 is now old and buying parts for it new whilst easily available, is hellishly expensive. So I have made a stupid offer on a running donor car and if I get it I'll be stripping everything out of it. Driving a 30 year old model is great, but you had better have a spare car for parts I pity the W116 owners trying to source obscure parts today. I love the car so I'm happy to spend on it, but one needs to be careful about owning a classic no matter how nice it is.

Thanks for your help guys.

Cheers Mat

Can a Bosch centre recondition it?
I had the fuel distributor for the Spirit (Boshc K-Motronic) reconditioned by Bosch and it was a fraction of the price of a new one..
Otehrwise, an Uzi will fix it...
Regards,
Brian

 

[Styria]

Matt, I have a selection of fuel distributors - however, they may be different to your 420 unit. Also Matt, from memory, there is a black switch (I think) that is part of the fuel distributor, but it can of course be replaced. I have a spare one of those. A while ago, someone had problems with a car not starting and replacing that unit fixed the problem. Sorry I can't be more specific - it was a few years ago now. Regards Styria

 

[260ebenz]

Ok guys it is the fuel metering/distributor unit, how do I know you ask? Well fitted new plugs totally dried out the cylinder bores and the entire intake system took ages!!!!!!!!!!!!!!

So then I pulled the fuel pump relay and whilst young Harry took great joy in turning the engine over to start, I opened the throttle wide up and poured 40mls of fuel down the opening. Presto engine spluttered straight away I repeated three times and he is burning the fuel straight away.

So despite having excellent fuel pressure and flow at the injectors it would appear something in the meter or distributor has called it quits leading to substantial flooding. Hence the no starting issue and it would explain the excessive black smoke at start up I was getting before the whole thing died. So the search is on, for an entire fuel assembly not cheap!!!!

Lesson learned people, despite what some think a W126 is now old and buying parts for it new whilst easily available, is hellishly expensive. So I have made a stupid offer on a running donor car and if I get it I'll be stripping everything out of it. Driving a 30 year old model is great, but you had better have a spare car for parts I pity the W116 owners trying to source obscure parts today. I love the car so I'm happy to spend on it, but one needs to be careful about owning a classic no matter how nice it is.

Thanks for your help guys.

Cheers Mat

Hi Mat, where abouce is the donor W126 for sale?

Certainly is an annoying and ongoing problem with the Gov keep at it mate!

What is the going price for a 2nd hand fuel metering distributor for your 420?

Cheers.

 

[Oversize]

I just remembered why I have so many cars!!!!!

Swap it with a known good one, or have it repaired. Don't buy a new one. I believe it's common for the central plunger (metering piston?) to seize in the bore. If you bridge the fuel pump relay terminals and there's no resistance when pushing down the air flow flap, that's your answer....

 

[mathew]

The black thing on the fuel unit is a EHA valve and that's bee replaced. The centre piston appears to move freely but I suspect it's leaking fuel down into the air intake manifold. The quote was from the classic centre in the US I have dealt with them on many occasions, great bunch of blokes but that's to many dollars for a club run only car.

Sadly no one in Australia overhauls them any more, Bosch in Melbourne offered to send it away for overhaul but they couldn't quote me or give me a time frame. Hence I thought for the cost of a 2nd hand part, I could buy a whole car full of parts. Hopefully heading to Melbourne Saturday to pick up a nautical blue 1989 420SEL with grey interior. Interior is like new so anyone needing some interior parts message me and we can do a deal.

Can't wait to get the old boy running again he has been sitting out the back begging me to drive him.

Cheers Mat

 

[BenzBoy]

Where would Bosch Melb. send it?
I am surprised you can't get it overhauled in Sydney. Are you sure this is correct?
If so, it's bad news; very bad news.......
Regards,
Brian

 

[Oversize]

Bosch has wound up many things in Australia. I have a friend that used to work in their automotive section and now much of it has gone overseas. Only yesterday I discovered a Bosch parts list for 6.9 stuff but I doubt it'd be much good now (but I won't throw it out)....

After searching through my old business cards I found the contact details of a company that rebuilt my warm-up regulator around 5 years ago. I really hope they're still in business, because they did a very good job at a more than reasonable price:

Ken Airs Petrol Injection Services P/L
Louie Binios - MD
5-9 Baillie Street, North Melbourne, Vic., 3051
Ph (03) 9329 7559

 

[mathew]

Well gang I have rung every state and Territory today and all I have chased up is, we used to but no demand any more. You can't get this done in Australia anywhere, many are happy to send it to Germany but we all know what that will mean. So currently I am ordering a kit to overhaul it myself out of Canada would you believe and picking up a spare 420SEL for parts. I have just learnt a valuable lesson in why old can be very expensive!!!

More importantly W126's are being snapped up all over the world and stored for parts I spent today looking for used ones and 420SEL's used to be easy to get a hold of, not any more people. So if you own one get one for spares before you can't!

Mark thanks for the contact if they can rebuild I'll be sending mine dead on off ASAP so as I have a spare 20 years from now.

Cheers Mat

 

[BenzBoy]

Bugger...
Such a useful word for moments like these...
Regards,
Brian

 

[Tony66_au]

Bosch in Germany have a Heritage parts refurb service and are doing many now unavailable items such as AAV's and fuel distribution modules.

Every year they add a handful of on demand parts available changeover or straight purchase and the prices are probably half the genuine price but with a 12 month guarentee.

I know Bosch still have all the dies and bits to produce parts new and the whisper is that they need to see demand before they tool up and do batch runs.

If you google the Bosch part number for the M117 D jet AAV the website is on the first page of results.

In Short id say they are testing the market with refurbishment and seeing how demand is on hard to get parts before they make new units.

 

[mathew]

Mark a million thankyou's!!!!!!!!!!! Your guys Ken Airs Petrol Injection Services P/L
Louie Binios - MD
5-9 Baillie Street, North Melbourne, Vic., 3051
Ph (03) 9329 7559

Still overhaul these for $561 for a V8 one, needless to say I'm one very happy camper will be sending off shortly. Once again I can't thank you enough, I have spent three days ringing all over OZ to find someone that can still refurb these.

Thanks heaps Mat.

 

[Styria]

Matt, let's hope that's the problem. Difficult to understand how the car would have stopped so suddenly at the time when it did. Regards Styria

 

[260ebenz]

Mark a million thankyou's!!!!!!!!!!! Your guys Ken Airs Petrol Injection Services P/L
Louie Binios - MD
5-9 Baillie Street, North Melbourne, Vic., 3051
Ph (03) 9329 7559

Still overhaul these for $561 for a V8 one, needless to say I'm one very happy camper will be sending off shortly. Once again I can't thank you enough, I have spent three days ringing all over OZ to find someone that can still refurb these.

Thanks heaps Mat.

Excellent news Mat and let's us know when the overhaul is done and the 420 is up and running again.

Cheers.

 

[Oversize]

Oh thank God! I was starting to think all my old contacts could be duds now... Yes definitely fingers crossed that's the problem. Now if only we can find someone that still makes custom camshafts....

BTW it may pay just to double check everything you've done before sending the distributor off for repairs. I know someone who spent at least $2K on replacing parts through another mechanic, after having a go himself in the backyard with no luck. He'd substituted a coil that he believed was ok, but it turned out not to be the case. I refer to it now as the $2K coil!!

 

[Tony66_au]

Matt, let's hope that's the problem. Difficult to understand how the car would have stopped so suddenly at the time when it did. Regards Styria

Oh I know how lol

Had 2 K jet Volvo's do that EXACT thing when the fuel dist module shat itself and a K jet 450 that wont start on fuel althought theres spark and fuel but will run when started on LPG and flicked to Fuel over 2800 RPM although it blacksmokes a bit.

 

[Oversize]

Tony I knew this would interest you, as you mentioned getting rather frustrated in another thread!!! Could it be a warm-up reg problem? I think I have similar issues quite a while ago with Skye, although I could get her to fire, but she just wouldn't idle. Ken came to the rescue!!! Ideally you need a special fuel pressure gauge and the correct chart of temp vs pressure so you can check it before sending it off for repair.

 

[Styria]

Ideally speaking, as Matt has indicated, one should have a WORKING spare care for parts, especially when it comes to our 116 and 126 models. I have always endeavoured to follow that principle, but lack of space, and slow deterioration of parts, can then become an issue. Also, like perhaps in Mark's case with all the cars he has as spares, chances are that some, or many, of the parts may not be in good condition and threfore not be suitable for spares. I am talking about Ball joints, struts, Air Cells etc. etc. In other words, anything at all that could stop a car from functioning.

I have several fuel distributors on hand, for instance, which I have collected over a number of years. After all this time, I certainly cannot remember which came off well working cars, nor the models, and I have no way of knowing if any of them would work properly. I have tried to store them in a mixture of fuel/two stroke oil for lubrication purposes, but who knows ? Therefore, I should just fit each and everyone in turn to Gleaming Beauty which is running quite well at the moment, and detremine if they are useable. The same applies to fuel pumps, ignition modules etc. etc. BTW, I have dismantled one Alloy unit (as distinct from the cast iron ones), and I reckon I would have buckleys of rebuilding one, let alone set one up. The way I see it, each port needs to be calibrated independently. Clearly beyond my capabilities. Regards Styria

 

[mathew]

I'm pretty sure that's my problem guys I have brought an assembly second hand to confirm as it was cheap. My ignition system is spot on but I did replace coil to double confirm. Like I say with the fuel relay removed and pouring a cap full of fuel down he splutters to life straight away despite the engine being very cold (winter has come to Wagga). As soon as you fit the relay and let the car supply fuel it simply floods out and yes the pressure regulator has been replaced. I guess it one of those patience things lol

Cheers Mat

 

[Tony66_au]

Carson and Murphy Who are legendary Volvo workshop guys explained it to me years ago.

In a nutshell the K and KE Jet mechanical systems HAVE to be clean and are intolerant of crap in the fuel, and youd think that regular filter swaps would take car of this but over time varnish and additives build up in fuel lines and something as simple as a fuel additive can flush this loose.

In my case it was a dry fuel system (450SE) and when I added 20 lt of Premium ULP, a new fuel filter and primed the system the rot set in as it initially started and idled high on fuel and after being left for a few days is again started and idled on fuel but on the third attempt it ran for 10 or so mins and then died and refused to be started on fuel again.

After a lot of mucking about and flushing fuel through the system I just walked away to concentrate on the green SEL.

I have some glass sherry flagons I use for fuel rail flushes and I did flush it through for 10 mins and noticed yellow ish particles in the flagon at which time I grabbed a second flagon and fresh fuel and repeated the process with a cleaner sample.

BTW I used BP Ultimate to fill the tank and for the flush using a parts wash pump and separate fuel lines from the filter join to the engine bay, you can use clear PVC as I do or standard fuel line if you want to.

BTW the third glass flagon I use for brake lines with a solvent approved pump and usually parts wash fluid with a Metho rinse followed by a brake cleaner blast (Usually half a can per long line) to remove any residue or moisture.

Anally retentive? sure lol

But when you see the crud that flushes out its not a bad idea.

 

[kunbarrie]

remove the 3 screws holding the fuel divider to the baffle plate housing,lift the divider a few centimetersout of the housing,bridge terminal 30 and 87 in the fuel pump relay,to charge the system,slide your finger under the divider and push plunger up ,and down,if fuel drops out from around plunger thats your problem,or if you are have a newfangled video camera that can see around corners,hold open baffle plate ,insert camera and check for leaks,you can call that a fuel divider colonoscophy,[LOL]