M130 Let’s tune it together

[MarkCan]

It was a beautiful day today so I spent few hours on the engine again.
After going over the linkage tour once more I took stuff apart and took measurements. It wasn’t crazy bad but far from perfect. I still got some minor things to iron out but overall I’m happy with what I achieved today.
Here is the latest video of the engine idle. (550rpm, little low I think)
https://youtu.be/EswYQg0PfxU

Mixture adjustment is next.

This thread is the continuation of of several others, last one here;
https://www.sl113.org/forums/index.php?topic=33458.0

[MarkCan]

Forgot to mention,
In order to achieve fully closed position on the Venturi the connecting linkage had to be adjusted to 305mm (ball centre to ball centre).

[MarkCan]

I added few hours to the project today.
Put new plugs in, NGK BP6ES gap at .030. (Old plugs confirmed rich condition).
Adjusted idle mixture to the max lean position for the idle and it still idles rich. Look at the attach video. Engine can comfortably rev to 1500rpm w/o adding fuel.
New king lead with 1Kohm resistance. Total loop resistance for each plug is @ 9kohm. Still not a perfect 6k but a move in the right direction for sure. The exhaust and ignition cycles cleaned up quite a bit again.
Here are the examples, with the ignition starting on cylinder #1 and exhaust starting on cylinder #6. Samples were taken with the engine running around 600 rpm. Valleys and peaks move by one position when exhaust pickup pipe is placed on the other side of the exhaust pipe. In other word all good there.

[MarkCan]

Rich mixture video link;
https://youtu.be/Li6YQfA4xaY

[Pawel66]

What about fuel mixture for the full revs spectrum? Do you have it adjusted to where it should be? You may not be able to compensate with idle adjustment screw if the full load is rich, I think.

[Cees Klumper]

The title of this thread suggests that you may be a fellow fan of this car channel:

https://youtu.be/SG4DRspZmG8

"Let's diagnose this ... together!" (Says Diagnose Dan - very enjoyable and interesting content).

Sorry, back on topic.

[MarkCan]

The title of this thread suggests that you may be a fellow fan of this car channel:

https://youtu.be/SG4DRspZmG8

"Let's diagnose this ... together!" (Says Diagnose Dan - very enjoyable and interesting content).

Sorry, back on topic.

Yes, yes I’m.
Dan is very positive and systematic in his approach.

Back to the subject,
I’m not crazy about more adjustments on the IP at the moment, ( that’s not what Dan would do 🧐). As a matter of the fact I already put the idle adjustment back where it was originally.
Low/lower pressure injector release will cause more fuel to be delivered. Let’s take care of that first. For now I got the injectors soaking in Jectron and I’ll put them in the ultrasonic cleaner tomorrow. I need to run few tests before I decide on the solution. I may even double dip to be able to use more aggressive cleaner if only my machine will be powerful enough to do it. Till than...

[mrfatboy]

Make sure you have :

1) good injectors
2) non leaking CSV
3) linkage properly adjusted
4) working WRD (not stuck open and fully closes when car is at operating temperature )


Do a search. There is detailed info on how to check and fix all the above.  Then start tuning. 👍

[MarkCan]

Make sure you have :
1) good injectors
2) non leaking CSV
3) linkage properly adjusted
4) working WRD (not stuck open and fully closes when car is at operating temperature )
👍

At this time subjects of points 2, 3 and 4 are already confirmed good.
Injectors are my main concern. There is also one new observation I made last night while comparing 230 and 280 IP. The Idle adjustment screw on the 230 is very pronounced and super easy to engage while on the 280 pump it takes some time to engage properly. The clicks are not as pronounced either.

I think that is important that I let everyone know that I’ll not be just throwing money at this engine to see what happen. Anyone with enough financial resources can do that. The objective here is to fix stuff and bring it back to its glory days. I know I have a very strong base. Once I’m satisfied the engine will go on the stand for cosmetic purposes.

[MarkCan]

Looks like the ultrasonic cleaner is doing it’s job just fine.
https://youtu.be/CBowRHbHDwQ
All 6 injectors were fully submerged in Jectron overnight. This morning fluid looked a bit darker but still clear. You can see what happens within a minute of me turning the machine on. So far a ran it through two 5 min. cycles. I’ll let it soak again, move it around and run few more short cycles. Solution is really dark and ugly looking now. I may run to the store and grab a fresh bottle.

[Pawel66]

I have been there as well - please let us know the success rate.

[MarkCan]

There is definite improvement in the spray pattern. Better atomization, not perfect yet but definitely a big improvement. I would love to comment on release pressure but the gauge decided otherwise and packed it up. I got a new one already and will see if I can run another test later on.
I need a little help in the video department, what’s best to use as the phone holder?
I got the tripod and the professional camera but that would not be the right choice.
I don’t want to get the diesel all over it while filming.

[mrfatboy]

Place the injector in a glass jar. That way you can see the spray pattern through the glass and contain the liquid at the same time.

[Shvegel]

I generally see about 220ish for opening pressure. Much more important for a clean hot start is the residual pressure the injector holds after you pump it up. I don’t remember the spec but do remember thinking it was unrealistically high.  If you see 30 PSI after 30 minutes it is probably OK.  You just need enough residual pressure to keep the fuel from boiling in the fuel lines as the engine cools.

[MarkCan]

I generally see about 220ish for opening pressure. Much more important for a clean hot start is the residual pressure the injector holds after you pump it up. I don’t remember the spec but do remember thinking it was unrealistically high.  If you see 30 PSI after 30 minutes it is probably OK.  You just need enough residual pressure to keep the fuel from boiling in the fuel lines as the engine cools.

Thank you
I'll order yet another gauge with even lower scale to make more precise observations of those pressures.

[MarkCan]

There is great improvement in the spray pattern on all injectors.
Since I’m really busy with other stuff and the M127 engine I’ll let those injectors soak  some more and than try to back flush again.
As for the IP I’m little bit concerned about the lack of the clicking feeling on the idle adjustment. I know Joe mentioned before that is possible to unscrew it internally if engaged with the engine running. I haven’t done it but I’ve no guarantee that someone before me didn’t try. I guess the only way to confirm is to take the plate off and look.
Will get to it soon.
I got a tree to plant and bark to spread 😀

[MarkCan]

I had another crack at the injectors today. After soaking them in diesel purge for few days, I run them through few cycles in ultrasonic cleaner. I’m very impressed with the improvement. Spray pattern is excellent, very close to new. Opening pressure right on 240psi. I’ll take a video tomorrow in daylight.

[MarkCan]

I have been there as well - please let us know the success rate.

Pawel,
Two short videos of release pressure and spray pattern are at the links below;

https://youtu.be/v-cvc7uY8gQ

https://youtube.com/shorts/Q-BR_yinikI?feature=share

All 6 injectors are within 10 psi or less
Do you approve? 

[Pawel66]

Of course. And I would be happy if it works!

I had a similar results. Then some time passed. Then I installed them back, they were working for some time. Then I checked them again. And they were leaking again. I am still an optimist, just better informed now.

But Mark - happy if you succeeded. The procedure does not look much different from what I did.

I hope all of that is because my injectors were just in a worse shape than yours and you will be fine.

[MarkCan]

Getting better but not there yet.
With the improvement from the injectors there is very little difference in the idle. Mixture  is very rich. Now with the better atomization of fuel I can easily reach speeds of 2000rpm with opening the intake only. Without touching the IP (linkage disconnected)
Time to study the pump little more. I have nothing in my manuals on that specific model and I’ll appreciate your input very much.
Here is my pump model number;

[mrfatboy]

At this time is the idle adjustment screw maxed out in the lean position(counter clockwise) ?

What is your shim thickness under the BC?

Assuming the internals are working correctly it seems like adjusting the rack screw leaner would be my next step. That will lean out the pump across all ranges.

Maybe somebody messed with the rack screw and turned it the wrong way. I seem to remember it’s reversed from the idle screw. You will need to verify.

[MarkCan]

Moving the idle adjustment makes very little difference if any. There is no pronounced click but engagement is definitely taking place. I plan on removing the plate tomorrow to confirm the functionality of the screw.
This engine/ pump combo is of the 280SE and slightly different than SL. The rack will be the same but other adjustments points may very a bit. Last thing I want to do is turn the wrong screws. I’ll try to post more pics tomorrow.

[Pawel66]

This is hexagonal screw head moving between two leaf springs, all of it lubricated - you may or may not have a pronounced click, but you will feel the screw turning and locking as its head will lock between the leaf springs.

Mark, you say your mixture is very rich on idle. How does it look like across the ranges? How do the plugs look like? If the FIP is somehow set to be very rich across ranges, idle screw may not be able to compensate for it.

What we can work with is the main rack adjuster, idle adjuster (bearing in mind that for the main adjuster left is rich, right is lean, for the idle right is rich, left is lean as mrfatboy said) and the BC shims. It takes special equipment and procedure to work with other adjusters (white and black screws under the plate) and we do not touch them in essence.

You may want to chose your strategy: working with main adjuster or BC shims to check/adjust the whole range if you want to do it. I chose to insert 2mm shims under BC and work with the main adjuster. This will have to be quite crude adjustment as you need to check CO under load and be equipped for that, so I just used spark plug color for assessment. In any case - I did the full range first, then moved to idle and warm up adjustment.

If you taking the back plate out - there is an oring that you may want to replace, check it out.

[MarkCan]

At this time is the idle adjustment screw maxed out in the lean position(counter clockwise) ?
What is your shim thickness under the BC?

Yes, on the first point.
1.4mm o the second.

With the current barometric pressure of 29.999 inhg BC pin is extended from the enclosure by 0.2mm.
There were total of 4 shims under the BC. .5, .52, .28 and .1mm respectively for the total of 1.4mm.

[MarkCan]

I think the bottom of the hex nut to the top of the extended pin will be more of a relevant measurement here.
It is 21.2mm at the moment