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  #61  
Old 12-18-2012, 12:58 AM
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Either way

Either way, I won't be using my finger, just to be safe. I don't think we need to worry about what might happen, as I am not going to try it. However, I am going to try to look more into the IP. I am going to try testing few simple things people have mentioned hear, but if none of them works, I will move on to trying to remove the Number One Delivery Valve. Does my previous post (#55) accurately depict what has to happen initially? Once I take it off, any further suggestions ideas (aside what has already been said)? Thanks again everyone for sticking by me.
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  #62  
Old 12-18-2012, 01:08 AM
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Quote:
Originally Posted by McCedesBenz View Post
To Everyone: Thanks for picking up right where we left off. I really hope this can get somewhere.
To Diesel911: Unfortunately, I can't answer your questions with 100% confidence in my memory. I KNOW for a fact when I pumped the hand primer fuel came out of the return line. When cranking, I am ALMOST sure fuel came out of the return line, but I was distracted by my hopes that I would see signs of life. I will double check this.

I do certainly have an MW type Fuel Injector Pump. I would like to do what you said, but I want to be absolutely sure I am understanding you correctly. I am very nervous about tinkering with any part of the IP (as I have hear a few horror stories). I want to make sure I understand exactly what you mean. I tried to look it up, but if you could describe what you mean by "Delivery Valve", "Delivery Valve Holder", "Delivery Valve Holder Spring", and "Center Valve" it would really help. I don't mean to be a pain, but I want to make sure I do the right thing. In short, is the "Number One Delivery Valve" the object I circled in green on the attached picture? I had actually tried to take this off based on some earlier advise, but got scared when I tried with *some* force and it didn't seem to budge. If this is in fact what I want to take off please let me know. I also put red X marks over the bolts I am under the impression I don't want to touch. I did try to research the meaning of everything and will continue to do so, but if you can confirm that I want to take off the green circled thing (which I believe is the Number One Delivery Valve) that would be great. Also, Number One does refer to the front most one right (the one I circled)?


I'm sorry that I don't know the names of everything, I will try to work at it, but while I am ignorant, please try to help me learn. Any information on what these parts are and what I want to touch and shouldn't touch would be great. I won't try to hide that I am afraid to touch anything near the IP, but if I am confident what I will do won't make more problems, I'll go in.
OK in your pic stay away from the 13mm Nuts like the ones with the Red Xs.

In My pic
1= The Delivery Valve Holder (in the Mercedes Manual sometimes reffered to as Pipes)

2= The Delivery Valve Spring

3and 4 are the Delivery Valve Assembly (a mated pair, I think the Mercedes Manual calls them Pressure Valves) and the Center Valve only goes into one side of the cylindrical Valve Body. The circular groove around the outer Valve Body is there to help reference what end goes which direction; you have to note that when you remove it.

5- Is the Copper Crush Washer.

If you remove 1 through 5 you should be able to look and see if the Plunger goes up and down.

Also note that when you Drip Time the Fuel Injection Pump you remove 1, 2 and 3 and reinstall 1.
After you are done drip timing you remove 1, 4 and 5. You put a new 5 in and replace 4,3,2 and 1 and Torque 1 to the proper spec.
So removing the above mentioned items is safe as long as you do not drop and lose something.

The above applies to MW Fuel Injection Pumps only.

Any time the Delivery Valve Holders are to be removed you need to clean the dirt out of the threads and the top of the Pump so none gets inside.
Attached Thumbnails
IP Issue? (please help)-delivery-valve-parts-dec-12.jpg  
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  #63  
Old 12-18-2012, 01:16 AM
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1 More Question.

Okay great. So I am feeling confident I know what I need to take out. In one of your previous posts you said only to take out the Number One Delivery Valve. Does this mean I can only take out the one closest to the front bumper or were you referring to something else? I just want to be sure. If it isn't an issue, I'd like to be able to take out all five (if taking out the first one shows a problems the others might have). Thanks again!
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  #64  
Old 12-18-2012, 09:13 AM
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Quote:
Originally Posted by Jooseppi Luna View Post
OK, now I'm curious. Why did you have no flow?
I "thought" I had no flow because everytime I opened an injector line and cranked the engine I only got a minute "dribble" of fuel which I assumed to be only residual fuel draining out...I was expecting a constant healthy stream of fuel under pressure from the IP...

I did not realize/understand that the IP only puts out a tiny amount to each hard line during each cycle...I was picturing in my mind more like the fuel rail on a gasser...always full of high pressure fuel which would "bleed" profusely if opened up
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  #65  
Old 12-18-2012, 09:47 AM
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Quote:
Originally Posted by Diesel911 View Post
Try this; put your Bathroom scale at about the level of the Fuel Injection Pump and put your Thumb on the middle of the Scale and lean down on it with your Body Weight and see how many pounds of pressure you come up with.

I am pretty sure if I put My Thumb or Finger over one if the Delivery Valve Holders and lean on it I could hold back more than 60 psi.

OK, so what we have here is a person who not only randomly covered the delivery valve holder with their thumb (which might be able to contain 5 psi), but also decided to lean his entire body weight over the top of his thumb, while the IP was still in the vehicle.

Do I have that right?

Is this your argument of why not to do it?




Quote:
Originally Posted by Diesel911 View Post

As an example an Air Compressor will typically put out 100-125 psi. Some Air blowing jobs require a Need type nozzle on the End to cean small passages.
If the Needle does not have the safety side vents and you press one of those skinny needles against firmly against your Skin and give yourself a blast you have a good chance of shooting some Air into yourself and that is a realativly low pressure.
Yes, that would be correct. The reason is that the compressor has the capability of sending air through the nozzle at very high velocity due to the existing tank pressure. It is the velocity of the air that will cause a quantity of it to be injected into your hand prior to the force of the air moving your hand off the nozzle.

In this specific scenario, with the nozzle that you described, the output area of the needle is extremely small and the force developed by the air against your thumb is also quite small. So, your thumb can probably remain on the nozzle and it will receive the very high velocity air jet at 100 psi.


The two examples you cited, one ridiculous and one legitimate, cannot be more divergent from each other.
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  #66  
Old 12-18-2012, 10:19 AM
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Ridicules or not.

I mentioned the compressed Air to show that at 100-125 psi is enough to inject the Air into your Body; because that has actully happend to People.

I mentioned the Garden Hose and My Thumb holding back 60 psi to show that it is possible to physically hold back more than 2-5 psi.

Added. I was trying to show that a lower pressure can cause issues.
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Last edited by Diesel911; 12-18-2012 at 10:55 AM.
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  #67  
Old 12-18-2012, 10:32 AM
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Quote:
Originally Posted by Diesel911 View Post

I mentioned the Garden Hose and My Thumb holding back 60 psi to show that it is possible to physically hold back more than 2-5 psi.
It's also physically possible jack the vehicle off the ground, put it in drive and hold onto one of the tires.............if you're so inclined.............
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  #68  
Old 12-18-2012, 11:06 AM
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Originally Posted by Brian Carlton View Post
It's also physically possible jack the vehicle off the ground, put it in drive and hold onto one of the tires.............if you're so inclined.............
Yes, I admit I have used Jack to raise the Vehicle off of the Ground (but normally I put it in Park and block the Wheels before that) and accidentally left it in Drive.

After that I have also put a Hand hold on the Tires/Wheels while they were on the Car to see if there was any abnormal Play.
In fact with the exception of putting the Car in Drive I have done that many times.

No doubt some time in the future I will be doing it again.
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  #69  
Old 12-18-2012, 06:19 PM
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Off Topic

Unfortunately, I feel like we have gotten a bit off topic. I created this thread to try to get ideas on my IP issue. If someone can confirm to me that I should take out the Number One Delivery Valve, that would be great. (Does this mean I can only take out the one closest to the front bumper or were you referring to something else?)

I have a feeling my issue is that the Delivery Valves are blocked or that the springs are stuck (or something like this). Any advice on diagnosing exactly what is going on or how to rectify these issues would be awesome.
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  #70  
Old 12-18-2012, 08:46 PM
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Not all five spings or pistons in the injection pump are stuck or the car would have not run previously. So that to me is currently a dead end.

I am going to suggest a test. Pump the new primer pump. As it pumps up you should hear a kind of squeel as the relief valve opens. The pressure of pushing the primer pump must increase or build up to the point of the squeel.

You just keep pumping the primer pump. Have someone then turn over the engine with the key and you still priming it. You can have them sitting in the car waiting for your signal to crank. May as well have them pressing the fuel pedal down at the same time to maximise fuel delivery if you have any. Do put a container of fuel feeding the lift pump.

If no fuel comes out of the open line fittings on top of the injection pump then it is absolutly certain the injection pump is shut down. Possibly a stuck rack.

This is post #69 so hopefully you can accomplish this with no variation. Done the way I suggest it is conclusive. With no variation from the proceedure I mention and post what happens. Change any component of the test and it is meaningless. Lets get this nailed down as it is not rocket science. Five or so turns of the engine are quite enough for this test. No sense working the starter hard.

Even if wvo had created a varnish in the injection pumps piston bores it would not get all of the pistons stuck at the same time. The odds of that are lotto like.

For example you do not stop pumping and jump into the car and crank. Or stop priming because relief valve pressure squeel is present. But do stop pumping if the back pressure to pump remains very low and almost nonexistant . To build pressure you have to feel increasing resistance up until the relief valve opens and then it should remain pretty constant. Do put a container of fuel for the lift pump hose to pickup.

It is not the time to start pulling apart delivery valves. If the car had been sitting for ten years and never run since then perhaps the pistons in the injection pump might all be frozen.

One last thing. You mentioned you introduced high air pressure to inside the injection pump. Where on the injection pump did you introduce that? .This test by the way you should be able to accomplish in only a few minutes.

Last edited by barry12345; 12-18-2012 at 09:25 PM.
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  #71  
Old 12-18-2012, 10:51 PM
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Okay

Okay, I have a few things to check next time I have time to work on the car. As part of it, I will do the exact test Barry12345 suggested. I really want to nail things down too. Unfortunately, although I have tried to be methodical, my lack of knowledge has limited me. As far as I can tell, I have isolated the issue to some extent. Although I believe I already have done something very close to the test Barry12345 suggested, I will do that EXACT test.

Unfortunately, I will be away for a while, but when I get back, I will get back into things. As always, any ideas and information are always welcome. The more I know about IPs and jammed racks, the better I will feel.
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  #72  
Old 12-26-2012, 01:28 PM
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Happy holidays everyone! I think I have made SOME progress. As barry12345 suggested, I did some tests to hammer things down. I pumped the hand primer pump until I pretty much couldn't anymore. I know I was supposed to hear a sound, but I didn't notice it. I can't swear I didn't miss it. However, I am CERTAIN that some diesel was coming out the return line in my set up. Then, I tried to crank the engine and I observed something important. It seems like when I crank the engine, NO FUEL comes out of the return line. I am virtually certain the lift pump is not the issue (itself) because I tested it out of the car and I just changed it. However, if I crank the engine and pump the hand primer simultaneously, some fuel does come out of the return line. In all these scenarios, no fuel comes out of the IP. I am thinking that for some reason the cam that drives the lift pump (and/or the IP) is not turning for some reason. Any ideas are appreciated. Could a jammed throttle rack cause this? When I crank the engine, the engine definitely turning over.
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  #73  
Old 12-26-2012, 01:29 PM
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Just to add, plugging the return line at the back of the IP with vice grips cranking made no difference. Thanks again.
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  #74  
Old 12-27-2012, 11:01 AM
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As long as you had someone else crank the engine when you were maintaining pressure with the primer pump. Then the fault has to do with the injection pump in my opinion.

If you stopped pumping before cranking the engine we are still at square one. The pressure accumulated with the primer pump might deplete too fast.

If you got someone else to crank it with you pumping then we might be getting somewhere. The primer pump being constantly held at higher pressure would replace the lift pump for our purposes.

So even if the lift pump was not functional it would not have impacted the test. The test was structured to see how the injection pump reacted to having a known supply of fuel under pressure in the base of it.

If the injection pump was functional there should have been some output from the element ports. If you suspect the crankshaft is not turning in the injection pump there will be no output from the lift pump as a cam on the injection pumps crankshaft powers it. It there is some output from the lift pump at all then the injection pumps crankshaft is turning. As long as you followed the suggested test accuratly it is the injection pump. If you changed any component of the test it is inconclusive.
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  #75  
Old 12-27-2012, 06:54 PM
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clarification

Sorry. To clarify, I did have someone crank the engine while I primed the hand primer as much as I could. Nothing came out of the IP, but fuel did come out of the return. Then, I just had someone crank while I didn't prime and no fuel came out of the IP or the return. Thus, I think the IP has an issue AND the lift pump is not being driven. What could cause BOTH these issues? I'm hoping they have a something in common. Thanks!
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