Dog 350SE

[Nutz]

Here's what you're going to be on the lookout for Denis.Smash it upon sight.

[oscar]

Lucas theory??? Dancing Faires??? Anime electron fairies???  Those physics lectures I spent in the Pub all those years ago, look what I missed. 

Bloody hell Denis, what's doing? Not what I wanted to hear.  After a few weeks on holidays I come back to hear about your dog??  Is it moisture? Just kidding we've been there.

I really wish I could help and wonder if it's something simple.  I think from your previous thread your ECU's fine and you replaced much of the fuel lines.  The whole grounding theory holds up.  Even if nuts are tight the connection can be poor, but I assume you've looked into this before.  Is it possible a feed line from pump or filter is kinked or blocked?

I dunno. Going back to the fairy thing, I don't suppose the google ads below might help. 
Keep us posted. Good luck.

[Denis]

Hi guys

I got a hold of a good used fuel pump for 20â,¬. Staright from a 1973 350Se taht had 159000km...new pump right 

I'll keep you posted.

Denis

Paris, France

But...but... Nutz, us frenchmen never smash cute little pink ladies as in the picture 

[Denis]

Hi fellows

Good pump fitted - still not very good 
So I went back to basics and set the ignition to a static 10deg BTDC (Euro car). It started but took a while to catch on. Immediate shut off, and set timing to about 20deg BTDC static- starts much better still a low idle, not very smooth and with only modest response to the D-jet idle screw position....

What is this ?

I am going to test fuel pressure after the regulator tomorrow, just try finding parts like 8mm T fittings in France 

What is going on here ? The car feels normal on the open road but I want to look at cam timing.

QUESTION 1 : What is the EASY check to cam timing - chain stretch and position ?

Michaeld, was it you who complained about mercedes being tough to work on ? you are right (except for a 240D).

QUESTION 2 : How do you guys turn the bloody  crankshaft pulley on these V-8s ? On my 6.3, I had a 50mm socket, a short extension and a 1/2 inch ratchet - no problem at all and that car is known as being hard to work on.

But this 350 is WORSE, arrgh ! Now with an electric fan in front of the radiator, one could turn the crankshaft easily and save a bit of power and wear on the water pump 

Denis id getting very fed up with W116 dog car 

Please help !

Denis

Paris, France

[michaeld]

Denis,

Just had an idea: have you checked your throttle body?  A dirty throttle body COULD cause your symptoms.    A dirty throttle body would cause a car to not idle properly, and/or stall.  I'd say cleaning it's worth a try (AND it would cost you nothing more than a can of cleaner!!!).

Some other possible culprits: a maladjusted throttle stop; a bad idle speed motor; a vacuum leak.

It sounds to me like you are getting to the end of your rope in terms of spending money - the phobia of throwing good money after bad - when it may/may not be the fix.  Believe me, I've shared that fear!

Let's step back, scratch our heads, and think of CHEAP and easy fixes that you haven't tried yet.

And give us (or link us to it, since you've described it before) your symptoms: If I understand correctly the car has a hard time starting; when it starts, it runs roughly (at least sometimes); it seems fine at some RPMs but not at others.  Let us know.  We have to think like detectives and try to think of one thing that could explain ALL the systems. 

Anyway, if you haven't already done so, I would clean your throttle body.  It would be AWESOME if your problem was some dirty component that can simply be cleaned.

Can anyone think of other possibilities?  List them in order of cheapness and easiness for our good, albeit frazzled, friend Denis.

[John Hubertz]

Denis,

I'm also thinking that we need to mine a greater lode of D-jet knowledge, as that is a rare configuration on a 116, and we are a small group.

I'm going to post this entire conversation on a 107 site, and if someone knows of a site that has a lot of 280SEL 4.5 members please do the same.

SUCH frustration to have a poor-running hobby car.

[Tomi]

QUESTION 1 : What is the EASY check to cam timing - chain stretch and position ?


QUESTION 2 : How do you guys turn the bloody  crankshaft pulley on these V-8s ? On my 6.3, I had a 50mm socket, a short extension and a 1/2 inch ratchet - no problem at all and that car is known as being hard to work on.

Answer 1: Take the right (passenger side in LHD) valve cover off, and then turn the crankshaft with a socket until the marki on the camshaft is aligned, then read what it says in the crankshaft, should be quite closely aligned. I would say that if you dont here a slap of the chain during startup for about 2 seconds when you start the engine, there should be no problem. This kind of problem should come gradually and not suddenly as in your case.

Answer 2: at least in a 450 it is a 27 mm socket and short extension and rachet. It should be easy to turn (clockwise of course).

Although I dont know much about D-jets, I would still think the problem is electrical.
- In a totally dark place, start engine and do you see lightening flashes, then it would be your ignition wires, You have measured the wire resistances, right?
- You did try another ignition coil, maybe what you tried is also caput
- You should try another ignition box, mounted on the fender, borrow from a friend.
- Take a further good look inside the ignition distributor for cleanliness, corrosion and cracks, is the rotor perfectly good also from the bottom?
- measure the vacuum produced when idling
-
How do the spark pulgs look like ?

this comes to my mind,
salut.

[Denis]

John Hubertz !!!

Yes John, the timing was OK 8000km ago but no longer ! YOU had the SOLUTION !!!

I removed the right hand valve cover. The timing was well off by about 12 degrees !!! fearing the worse, I checked the compression. The car has between 9 and 10 bars in each cylinder, which is fairly steady but too low (who knows when the valves are opened now). So at least the engine has survived. Just to think, only 309 000 km and already an engine problem 

So the car starts, runs OK if very rich and has apparently not suffered from the crazy timing 

I suspect that the PO changed the timing chain but NOT the tensioner 
There are clear chain marks on the inside of the right hand valve cover. It probably jumped at startup.

Now unfortunately here goes MORE money. The problem with these cars is that it doesn't take long before you spend more on them than they are worth i.e; - you can find a better one for the cost of the parts 

What is the general wisdom on this job : chain, tensioner and any rails change recommended - my engine has the amber looking plastic ones.

Anybody can suggest euro parts sources for this ?

Danke sehr aus frankreich

Denis

[John Hubertz]

Denis,

Sorry to hear that's the problem.  I wonder, Styria, if he simply resets the timing, what are the odds of this happening a second time?  Seems a damn shame to waste a ton of money on new tensioners if he doesn't absolutely need them, and 309k isn't that much wear.....

John

[Tomi]

I am still not so convinced that your chain has slipped. Take both valve covers off and see if you have broken plastic rails on top. If yes, then possibly it has slipped a tooth.

The crank turns 2 revolutions as the cam turns one revolution, which means that the 36 teeth (if I remember correctly) of the cam to slip one tooth will displace the cam by 10 degrees and it should result in a displacement in the crank of 20 degrees.

Your 12 degrees is in the middle. But this is not the correct procedure to do the timing. It is not precise enough. You need to measure the valve lift with a guage and use some woodruff key to place the cam gear accordingly (special MB procedure I have never tried).

But if your right and left bank cylinders have equal pressure, it does not sound like chain slip. And the spark plugs from the different banks, do they differ?

[Denis]

The spark plugs all read rich and the compression on the right bank is closer to 9 bars while the compression on the left bank is closer to 10 !

I have rechecked the position of the crankshaft and indeed it is close to 20 deg, not 12 deg.

The problem is the cost of the tensioner, the best I can do is - 212â,¬ 

If anyone knows better, I am listening 

Denis

Paris, France

[Tomi]

212 euros, jeesus.
I did this job last year and I got it for about 60 e here. Not from the officia MB dealer though, but same piece,
try http://www.niemoeller.de/ in Germany if you dont get it cheaper in France.

be sure to change your top plastic rails as well if you do it.

The tensioner is a real pain to fit back. the trick is to use longer screws to start and then when it is closer and the spring is compressed change to the original length screw one by one.

[Denis]

Thank you Tomi

I had forgotten about Niemoeller !!! yes, the prics are high in France unless one calls a shop in Strasbourg or Colmar in Alsacia 

I will give Niemoeller a try.

Meanwhile, what do you fellows think of my idea of resetting the cam shaft timing as close to normal as possible and driving the car to the corner store only ? I would avoid the ridiculously rich mixture !

Denis

Paris, France

[John Hubertz]

Denis,

I posted your problem on a bunch of other boards, and the consensus is that you likely have a problem with your distributor - there are TWO sets of points, one for ignition, the other for injector timing.

Here is the text of the key response I've had - charles owns several D-jet cars and has years of experience with them:

(Denis,)

This is going to require patience. Don't assume something works, prove it. Don't skip a step and you'll keep those wits.

1. Start with clean plugs.
2. Check dwell and timing.
3. Disable the fuel system (disconnect the relay, the pump or the brain box) and make sure it starts well on ether.
4. Put a fuel pressure guage in the system in place of the cold start valve.
5. Clean the injection points.
6. Replace the rubber hose that connects the pressure sensor to the manifold. Make sure it is clamped.
7. Visually inspect all wires and plugs.
8. Loosen and then tighten the ground connections on the intake. One big hold holds down almost a dozen ground wires.
9. Turn the key to the point where the fuel pump runs. Make sure you've got a stead 32 psi (2 atu) reading on that meter. Turn it off and make sure the pressure doesn't drop immediately.
10. Follow the service manual procedure for testing the wiring and components with a meter. One of the more useful tests NOT listed, is to listen to the injectors for operation with a screw-driver pressed against your ear and the injector.

If you get past them and everything looks fine but it still doesn't run, I'd be surprised. Also if you get that far, think about replacing the rubber gaskets at the tip of the injectors. Unless you'd done that already in the past 5 years. They are critical for proper operation and get old and brittle and forgotten about out of sight and out of mind.

I have a 450sl with djet. I got lucky and noticed a broken wire at the brain box connection while just looking at the car during purchase. I pulled the harness from the car and bench tested each end with a meter. I fixed about a dozen wires. Some on one end, some on the other because they showed too much resistance between the contacts.

The moral of the story is that these old D-jet cars are subject to very pesky faults due to age. The system was not designed to work in such a fault laiden environment (it's not a Chevy). You are likely facing two if not three problems. Collectively, they are fustrating. Individually, you can find them and eliminate them.

-CTH

and then as a clarification:

Actually I was referring to the trigger points that control the fuel injection. On D jet, there are a second set of points lower down in the distributor, they slide in from the side. These tell the computer when to activate the injectors so that they are in time with the firing of the ignition system.

Chris

From all this, I'm going to say that if your chain hasn't slipped, it is likely the injection points for the injectors.  That would explain both the intermittent nature of the problem and the fact that rotating the distributor has an effect.

John

[Denis]

Dear John, thank you for trying to make me feel better but alas, I did all those things and the last check proved that there is something very wrong with valve timing : the car now sputters up EVERY TIME I try to start it with the ignition set way too advanced while it sounds like it is firing well after top dead center  To me that cannot be right and is related to the valves dancing at the wrong time.

And then the timing is well beyond the 3 to 7 degrees tolerated by most people and closer to 20. And the right cylinder bank has less compression than the left, another timing sign ! and then 9-10 bars on a Euro engine is terrible, it should be much higher and was not long ago.

Let it be known that I came dangerously close to sending this dog 350SE to the impound yard but it just looks so good...that it cannot be done - no more than sending Sir Sean Connery to sit in rags and beg for a pitance on some sidewalk on a rainy night.

There goes my budget again 

Denis

Paris, France