Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Thierry du Laos on January 07, 2019, 05:34:06
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Hi, my car had problems to start 4 months ago, and when she started, she ran on 4 cylinders. I had to go abroad 2 months, but when i came back she won't start anymore.
Ignition is correct, but when I open an injector line and crank, there is no fuel coming.
When I disconect the fuel line at inlet of the fuel injection pump the fuel comes out.
When I disconnect at the outlet of the injection pump, there is fuel also.
So I wonder what happens in the injection pump?
At the back of the injection pump there is two big solenoids. I believe there is one to open the fuel at start, but what is the second one for?
When I put 12 Volts at the upper one, I can hear it is moving!
Any suggestion?
How do these two solenoids work?
Thanks.
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It sounds like some of your injection pump plungers are stuck. I will let the pros chime in here to tell you how to test and fix since I have not done it before. You can also search on how to do the procedure on this forum.
The upper solenoid is the fuel enrichment solenoid. It always activates when the key is turned when starting.
The lower solenoid is the fuel cut off solenoid that I believe activates when in 3rd or 4th gear AND when the throttle is not depressed. There is a microswitch on the left side firewall connected to the throttle linkage that detects no throttle.
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Hello Thierry,
If you have spark on time, fuel supply with adequate pressure and volume, and compression, your engine will star. A fresh set of spark plugs is a good and inexpensive place to begin, check fuel pressure and volume also. You can check to make sure your injection pump is free by moving the rack back and forth, it should move freely. Yes the lower solenoid is a fuel shut-off emission device. If it is activated when the engine is off, the engine will not start. You can temporarily dis-connect it with no consequence.
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Thanks for these great informations.
There is spark and I put a new set of spark plugs in when I finished to rebuild the car, not long ago.
I will check the lower solenoid this weekend. I just checked the upper one, so far.
And a scily question is: How do you move the rack? Is it through the control lever ( that is connected to the external control linkage)?
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On the front of the pump (pointing to radiator) there is a black rubber cap that is covering the rack access hole. You may or may not have the cap after all these years.
You can insert a 5mm bolt (memory?) into the access hole and screw it in. From there you should be able to push and pull the rack easily if it is moving freely. The bolt should be about 30mm in length or so.
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Replace the spark plugs anyway. It's an inexpensive investment and may save hours of time. If the old ones are still good save them for future use. Not all IP racks have the threaded hole on the end. You can still feel the rack move slightly when the accelerator linkage is depressed all the way and released. You can also push it back through the access and feel it spring back slightly. Review some of the old posts on the IP rack. Here is a pic with some info......
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Thanks, I will have a look this weekend.
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Hi,
I had a try on the rack but it didn't move!
After inserting a screw in the rack (5mm) and pulled hard, screwing a nut. I could give it a little play. Approx >1 mm.
And the engine can start again, but not so good, like missing fuel.
My questions now are:
- What is the normal free play? 1 mm, more?
- Has anybody got a section of the pump to explain how its built inside?
- Shall I damage something if I pull more on the rack?
Thanks for the help.
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Thierry,
Just to give you a quick reference so that you find information on what you ask about:
Technical Manual
https://www.sl113.org/wiki/Fuel/Injection
In this thread you will find more specific info on how the pistons work in FIP
https://www.sl113.org/forums/index.php?topic=27193.msg194937#msg194937
You may want to study these.
Please wait for experts to respond, but to give you some quick answer before the experts chime in: it sounds like the rack in your FIP is stuck. It should move more quite easily and it should return forward to its resting position on its own.
In essence the pistons in FIP move up and down and also back and forth around their axis. These movements are related to movement of cam shaft and this rack (through levers). If this rack is stuck it usually means that one or more of the pistons are stuck.
If you go through forum you will see that some Members worked their way out of the stuck rack/piston situation by means of slowly and patiently cleaning and flushing the mechanism and gently putting it in motion. Others would send the FIP to be checked/rebuilt.
If I were you I would refrain from forcing the rack movement until you get advise from experienced Members.
As per my best knowledge, the rack can get stuck due to mechanical damage but also due to long period of non-usage.
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Děkuji Pawel.
I will go through these documents.
I worked for 3 years some 30 years ago, in Ruzinie airport with CSA!!
Nice country and people, and not too many tourist at that time..
Best
Thierry
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Thierry, I am at the Ruzine twice a week! The airport has been re-built about 15-17 years ago.
I fly from Prague to Warsaw, where I live. Usually LOT, sometimes CSA... You get a free wafer bar in LOT...
Czech people are great indeed! Very polite, good engineers. Country is beautiful wherever you go!
The town of Prague and the country were completely diferent than now even 15-20 years ago - massive change occured.
Humongous amount of tourists in Prague all year round these days! Crowds!
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Thierry,
You are in luck. It just so happens I have an old R20 pump on the bench.
Inserting the 5mm screw in the front rack access hole and pulling it out yielded ~10.5mm in travel. Pushing it in from its resting position was ~8.25mm.
These numbers can be slightly different depending on how the pump is tuned.
The rack should feel like it is spring loaded and should always return easily to its resting position after pushing and pulling. When moving rack it should glide effortlessly. 👍
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Other factors which effect the rack position and movement are; temperature/position of WRD, altitude (barometric compensator), accelerator lever position and engine rpms when running.
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Mrfatboy,
Mine is not moving that much and I am not going to push or pull anymore now because I don't know, following your infos, if the rack is in front or back!!
I understand that I have to remove from the top and find what is preventing the rack from moving.
One more question:
- By removing the 6 assies on the top, is it going to modify the calibration of the pump in any way?
Fro background, I had the car for 2 months July-August parked (Rainy season in our tropical region). Then in September I started the car to move her but she was running on 4 cylinders. I had her stopped again for more than month, and she wouldn't start anymore after that. Now she just started and ran by moving a little the rack.
So I suspect corrosion from water ingress? Hopefully superficial corrosion????
Let's see when I can remove the injector's fuel lines. I have to make the good wrench for that.
Thanks.
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There is a lot of great info regarding stuck racks on this forum. Use the search function for "stuck rack" or google "site:sl113.org stuck rack".
Here is an oldie but goodie from ja17 as just an example :)
https://www.sl113.org/forums/index.php?topic=886.0
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Thank you, I will read and try to work on the car next Saturday.
Best
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Hi,
Should the rack move easily a few centimeters and return forward to its resting position on its own when the FIP is installed on the car?
Mine moves easily only less 1 mm...
I removed the check valves.
I punched to release the cylinders and plungers.
The car starts again but missing 2 or 3 cylinders.
I think stuff got stuck again inside.
But anyway the rack has never been moving freely.
I wonder if I understood correctly the system?
- The rack moves longitudinally, and rotates the gears to control the fuel flow.
The gears go up and down to limit the cylinder play?
If I am correct, when I tap the cylinder, it should rotate the gear and push or pull the rack longitudinally? Eventually they both (cylinder and gear) come back up with the spring pressure....
I can tap the plunger until it is in contact with the follower and camshaft .
Thanks in advance for the info, because I am stuck also!!
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Finally I removed the cylinders. One was very difficult to remove, but it looked like locked with something inside.
It was moving but it wouldn't come out.
After many tries it unlocked free and popped out.
And freed also the rack in the same time.
So I cleaned all, inspected, and tomorrow I will fit everything back and I am confident .
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Post a picture of your progress if you can.
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I didn't make many pictures, just this one!!
And this Sunday I re installed all, and in the end the rack was not moving anymore, once again and the engine started but not enough fuel.
I removed all again, couldn't take the cylinders out, but got the rack freed. I can't understand!!!!!
Re installed the check valves etc... one by one to see if one number would be the one that locks the rack, but got everything back with the rack free. No understanding !!!!
I tried to start the engine, but no way, no explosion.
After that I stopped because my batterry charger died. So this week I will look for a new charger, and next weekend try again, and if you have comment, they are appreciated.
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Can anybody tell me what are the movements of the gears < > cylinders, given by the rack.....
I believe that the gears rotate, but what about the cylinders?
Do they rotate or slide vertical, to control the fuel volume in the chamber of the cylinders?
An other question is, could the thermostatic valve on top rear of the FIP, disturb the rack operations?
And can I remove it to check, with the FIP installed on the engine?
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An other question is, could the thermostatic valve on top rear of the FIP, disturb the rack operations?
And can I remove it to check, with the FIP installed on the engine?
The WRD (warm running device) which you are calling the "thermostatc valve" pushes down a mechanism in the FIP which slides the rack back (toward rear of car. Leaner) to its operating temperature position.
Even if the WRD slide valve was stuck closed the rack should be able slide forward.
The rack should move freely at all times.
If you inserted the bolt in the front FIP access hole in a running car you would see the bolt move forward as you rev the engine and move back as it returns to idle.
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The rotation of the pistons by the rack is what regulates the quantity of fuel. In addition the pistons move up and down (pushed by the camshaft below), and create fuel pressure to open the injectors. The cylinders are stationary. They are indexed by a pin and must always be installed in their "pinned-in -place) position. If the pistons cannot move up and down or turn in their cylinders, then the rack will be stuck. If you have an early BBB go to pages 07-10/3 thru 07-10/9for a good description and some excellent illustrations and photos of the injection system.
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Thierry du Laos,
I hope you kept all your cylinders in order? They are matched to the pistons and the tolerances are extremely tight(Millionths of an inch). If you didn't keep them in order start looking for another pump. If you did keep them in order look for someone to rebuild what you have. I know a fair bit about the inner workings of these pumps and you really are deep enough in where you can destroy the pump.
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Step by step I catch more and more the system.
Yes I have kept the order of the cylinders.
Unfortunatly I don't have what you call BBB.
Next weekend I will remove all again and have a better look with these infos.
Now that its been removed and cleaned, fortunatly it comes out easy.
What I meant by thermostatic valve is the kind of can on top. => Not the rear water thermostatic valve that opens or closes the air during starting.
In Laos, or around, I wouldn't give to anybody this FIP. I try what I can and if I cannot solve, I will send somewhere serious!! But I have to understand and make sure it is not a simple problem that I can do. Like CSS for eg.
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I meant this part
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That is the BC (barometric compensateor) or altitude compensator. See the wiki here for description.
https://www.sl113.org/wiki/Engine/AltitudeCompensator
Edit.
I just noticed that you posted twice. The description in the wiki will ultimately answer your question. But the short answer that you are probably looking for is the BC (working or non working) should not cause the rack to get stuck.
Here is the wiki on the entire FIP.
https://www.sl113.org/wiki/Fuel/Injection
Also, don't try to open up the BC. You will ruin it. 😖
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An other question:
- How do the gears turn the pistons, in the cylinder to regulate?
- What kind of mechanical device connects them?
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Thinking back on your past posts involving machine tools and remebering how much you did yourself on your car I assumed that where you were things might be marginal in terms of getting things done. I applaud your efforts.
The only thing that keeps the rack from moving is friction between the cylinders (Barrels) and the pistons (Plungers). The rack turns the pistons and the cylinder are retained in the pump. Unfortunately, I think you may be in trouble. When you removed the cylinders the little gears that turn the pistons may have skipped out of place. Added to that the pistons have springs in the bases (not the fat return springs) that are preloaded by twisting the piston as it is installed which preloades the rack so it closes. I don't remember where those springs are indexed in the whole scheme but if they index to the cylinder the tension is lost.
Lets worry about the first thing first. If you remove the side cover all the little bare steel slit collars with screws in them must be in the same orientation and should not be pointing in different directions. If they are messed up you might be done already.
The top can device is acrually a barometric compensator. push on the shaft a bit and as long as the shaft is free it is probably OK. Don't see how far it moves just make sure it is free or you risk altering it's properties.
BBB will do you no good. There is nothing on the internals of the pump. there is a Bosch rebuild manual online. Let me see if I can find it.
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The factory Bosch manual is listed under "MFI Repair" in this link. I had to keep clicking on the downloaded zip file to get to the manual.
https://www.pelicanparts.com/techarticles/911_MFI/TipMFI.htm
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There are certain external adjustments that you can make to an IP and even then you need to have some idea about what you are doing. Going inside the pump to mess with things is NOT a good idea even if you have manuals that describe how to do it and I think that no one here should ever advocate going in that direction. This is specialist work ONLY and not for the novice DIY kind of owner.
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Illustrations from Early BBB that may help...……….. It shows the early 2cyl IP for sedans but the concept is the same.
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Thank you for your understanding and informations, ALL.
The gears turn the pistons, but the cylinder is a different part that come on top to, guide and avoid the fuel to go down
I don't know if the cylinder is only moving verticaly or also rotates with the gear?
Moving verticaly, sure because it is the way to regulate the fuel quantity.
I don't think it rotates, and hope too, otherwise as you wrote: I am done.
Look at the pictures I have collected and put together to my understanding.
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I remember when I first open the FIP and the rack was locked. The rack got freed only when I took out the last cylinder, which was hard, the No3.
I check again now that you gave me all these informations.
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Thierry, when you remove the side cover of the pump, you will see (among many other things) 6 small pins in the upper part of the opening. These are the pins that are supposed to hold the cylinder in place and prevent it from turning. If the cylinder is turning with the piston, there is no pumping action of the piston (the hole in the cylinder and the slant in piston are not taking, lifting and giving fuel).
So cylinder must not be turning. Make sure you have all the pins there.
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The top of the pistons have a slant machined on the side of them. This lines up with a hole in the cylinder. By turning the piston you are exposing more or less of this slant which in effect alters the point where the piston seals and pressure begins to build. Think of it like holding the intake valve of an engine open. The piston travels the same up and down but compression is less because the valve is delayed.
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Thank you for these explanations.
So this Saturday I remove all again but found out that the rack was kept free for and aftward, if during inserting the cylinder aligned, I was pulling the rack forward!!!
A thing I didn't do before, and left it in central position.
I dont' know if it is real, but it worked. After installing all of the 6 cylinders, check valves and pipe connections torqued, the rack was moving nice.
I tried to start, but the engine was running on 3 cylinders !!!
So I disconnected the lines at the injector side. Put some plastic bags and crancked.
There was fuel on all 6 lines.
So I removed the injectors, and will take them to a shop who fixes the diesel engines! And ask them to clean and chek the spray.
Lets see for next????
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Here are some pictures....
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Looks very familiar...
And the spark plugs in those cylinders that were not woking - after engine running/cranking - were they dry or wet?
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Sorry, I cranked so many times with and without the spark plugs to save my battery, that it was not evident.
I tried that at the begining, indeed, and it was dry, that is why I went to check the FIP.
And found the rack was locked.
Now that I freed the rack and starts again, I look for the 3 cylinders I've lost...!
Yesterday I went to the Diesel shop! But they have a tool to test the Diesel injectors, with a gauge out of order.
After that, I think 2 or 3 injectors are not correct.
I talked to my Mercedes garage friend, he said that they used to soak them in brake fluid, and blow them to clean.
And there might be, at the Vientiane Lao-German technical school, a bench test for these old injectors?
So I am working on that... Step by step.
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If you think your injectors are flowing the same amount I wouldn't put the blame on them for the cylinders not firing. The later CIS system ran the injectors all the time and the fuel would just pool up behind the intake valve until it opened and dumped it into the cylinder. If the proper amount of fuel is reaching each cylinder it should fire. Maybe not perfectly but it should fire. Is there any chance you have missplaced the firing order of the spark plug wires at either the spark plug end or at the cap? I believe the rotation of the ignition rotor is clockwise but you should check by removing the cap and cranking the engine (watch the distributor cap clips as they tend to snag the rotor) After you verify rotation then find plug number one at the cap and make sure the rest follow the order cast into the valve cover.
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Move the suspected bad injector to another cylinder and see if the problem follows.
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I swapped two injectors and both spark plugs came black.
Then I bought new spark plugs as after cranking so many times they were getting not so reliable any more.
And all the cylinders are running now, but far too rich.
I tried to adjust the linkage to lean, but couldn't make it as I get out of adjusting range.
I blanked air succion hoses for cold start and brake power.
FPI disconnected, and resting in idle position, I open air admission and it runs properly a 2 000 rpm.
Also, when I push backward on the rack, it runs fine.
So I plan to reset all the linkages back to origin and plan adjusting the screw at the back of the FPI toward lean!!!
Maybe my injectors are better than previous, maybe I pulled too strong on the rack when it was locked, ...??
That's my understanding today...
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But it sounds like a progress!
As advised by the Members before, rich condition may be the result of many factors
- just adjustment (full load, idle)
- WRD sticking
- WRD shims
- barometric compensator stuck
- barometric compensator shims
and some others, I am sure, too.
My experience was that it took the car some drive for the new settings to come fully through. I know it is odd, but that is what I observed.
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Sorry what is WRD?
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Warm Running Device
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Do you think the WRD can interfere with the rack movement?
I have isolated the WRD hose and blanked it!
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The WRD will influence the position of the rack, but will not prevent it from moving.
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I tried to ajust the screw at the rear of the FIP, but can't reduce the fuel.
So as in the past I added a little shim to close 100% the air S-O valve when hot, I am going to remove it. To check if it is not what increase the fuel?
And after that, if it doesn't work I will have to send the FIP and injector to a specialized shop.
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Thierry, maybe I am repeating what you already know very well, if so - sorry.
WRD - as Joe said, it cannot lock the rack, but it influences it to increase fuel when engine is cold. The simple first thing here to test if WRD is responsible for rich condition is to check if it "switches itslef off" when engine is warmed up. You do it either by listening to the air loud noise as it is sucked through the little filter on the WRD (the noise must stop when engine is warm) or you unscrew the filter and feel with your finger if you get suction through the opening. If the device sucks air with warm engine - the WRD may not work ok and cause rich condition. Then there is the whole procedure with shims.
Barometric compensator - if it is broken it usually causes lean condition, bu for instance mine was stuck in the "up" position making mixture rich. Some reading here: https://www.sl113.org/forums/index.php?topic=12175.msg82217#msg82217
I think you may also have cold start solenoid on FIP - but I have not studied how to test it, so I do not know, sorry, my FIP has no solenoids.
Adjustment idle: just to make sure we have it correct - the knob outside (do not turn it while engine is running!) is just for idle, i.e. up to 1500-1700rpm more or less. Clockwise - richer, counterclockwise - leaner.
Adjustment full range: this is another adjustment we may decide to touch while carefully noting down the number of clicks towards each side. It is the screw in the back in the top right corner of the back plate of the pump. It adjusts fuel in the entire range of rpm. Clockwise - leaner (!!), counterclockwise - richer (!!). you can try this one if you are not afraid. You will need small flat screwdriver.
What we cannot touch, I think, are the partial load screws, light and dark, located next to the idle screw. What we also cannot touch is the linkage lever on the pivot at FIP.
Good reading as well:
https://www.sl113.org/forums/index.php?topic=28224.msg203581#msg203581
Hope I am not adding confusion....
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I have isolated the WRD hose and blanked it!
If you've isolated the coolant hose then you are running on permanent cold start which means rich condition.
remove the air filer from the WRD and monitor its function from there. Plenty of info on this site if you care to search.
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Thierry,
If your engine is running on all six cylinders now, make sure your linkages are still correct, make sure your WRD is closing, make sure your cold start valve is not leaking, make sure your timing is correct and make sure all is in good tune. Your fuel pressure should be up to specs. Now if it is still running rich, you can remove some round shims under the Barometric compenstator (altitude sensor). Removing one or more round shims will cause the engine to run leaner at ALL speed ranges.
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Thank you very much Pawel for this very complete summary. (dziękuję bardzo)
I will study this very slowly and try to apply on Satruday.
I will let you know further. Thanks.
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Stick,
I blanked the air hose of the WRD, not the water lines.
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Yesterday I took out my shims of the WRD and it seemed better on IDLE only.
Not on acceleration.
And I just learn with your comments that this screw works only for idle!!!
So I need to find and try the other screw that work on ALL regimes....
Cross fingers.
I hope that after trying everything I can succeed!
Because after I investigate around, there is no place that can bench test the FIP.
So only one way, I have to fix it myself.
That's why the garages in Laos take out the original engines and install Toyota or Nissan instead!!! Also a 300d Adenauer that had been the last king's car.
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Thierry,
If your engine is running on all six cylinders now, make sure your linkages are still correct, make sure your WRD is closing, make sure your cold start valve is not leaking, make sure your timing is correct and make sure all is in good tune. Your fuel pressure should be up to specs. Now if it is still running rich, you can remove some round shims under the Barometric compenstator (altitude sensor). Removing one or more round shims will cause the engine to run leaner at ALL speed ranges.
Thierry, I would do exactly what Joe says before getting to the other adjustment screw. Are you sure that poor engine work on acceleration is because of rich condition? It is often the ignition timing thing...
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Thierry,
Maybe, just maybe, after more than 50 posts on this, spending $30 and gaining Full Membership and thus being granted full access to do Joe Alexander’s excellent Linkage Tour in the Technical Manual would be a worth while expenditure at this point otherwise you are just going to keep going in circles
Garry
Membership Administrator
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Spot on, Garry...
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I make a brake going to France and will start over when I come back from begining. Like drain the fuel tank.
Thanks for the time being!