I've tried to find the thread where the injector pump timing method was given but to no avail. Could someone please direct me to it. I bought a '80 CD last fri. and hope to tune it some. Very tight car---NO rust. That's a BIG plus here in SD. Thanks in advance. Steve Sparhawk

Steve, I'm glad to hear you found a 300cd. Sounds like it's in pretty good shape. Did you get a good deal? andy

Steve, I've never timed an injection pump, but thought I would contribute this letter and response from the March/April 2001 issue of "The Star." It sounded promising, so I hope it helps.

Q: On my 1982 300SD's fuel injection pump, I've tried to adjust the "start of delivery" using the bent overflow pipe, but I don't know when to start timing the drips. Pumping the manual fuel lever produces continuous fuel flow out of the pipe, and the frequency of drips slows steadily. Until the drips stop, there no steady frequency. I'm also having trouble finding a 45-degree offset box wrench to loosen the injection pump; is there an alternative?

A: The drip timing specification calls for one drop per 10 seconds, but it's easier and less messy to time the pump using air instead of diesel fuel to set the beginning of delivery. Make up two clear hoses; connect one to a banjo fitting the same as the injection pump fuel inlet; connect the other to a cut-off injection line (or the bent tube you use for drip timing). Proceed as with drip timing, but instead of pumping fuel with the hand pump, blow air into the injection pump fuel feed. Stick the drip tube hose into a glass of water, and watch for when bubbles stop coming out of the hose. As you push the pump toward the block, it will become harder to blow air through the hose until the bubbles just stop. Lock the pump down there, and recheck by rotating the engine to 24 degrees BTDC on number one cylinder and blowing again. This method is accurate and repeatable within 0.5 degree of crankshaft rotation and is much cleaner than pumping diesel fuel.
To loosen the three nuts and one support bolt at the back of the pump, we use a regular box-end wrench and a wobble socket on an extension. The only unusual thing is that the throttle is supposed to be held full open while timing the pump.

__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

I'm assuming you searched the shop forum and didn't find it. Therefore, here's a link off site:

http://hsb.baylor.edu/html/easley/autofaqs/iptiming.htm

Enjoy!

__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

Steve,
If you want the factory manual method on how to drip time your injection pump, send me your address and I will be glad to send them to you. My scanner has stopped working, but I can make copies of the procedure and mail them to you. The whole process is fairly easy and the pages have pictures to guide you through the procedure. No special tools are required,but you will need a drip tube. You can make your own or get one from IMPCO for $17.95 phone no. 1-800-243-1220.
The procedures described in "The STAR" or by the people at Baylor University are in none of the Factory Manuals I have,and my manuals go back to the 180D('53-"62).Those procedures are not near as accurate as the drip tube method described in the manuals. I have used the drip tube method to time the dozens and dozens of Mercedes engines I have rebuilt. Never have I had to go back and re-time one of them.
The method in "The Star" and the people at Baylor is mentioned in a book of 1966 titled "Glenn's Mercedes-Benz Repair and Tune-up Guide" by Harold T. Glenn. But he goes on to state that the drip tube method is much more accurate.
Bill Lewallen Lexington,Ky. Where diesels purr and turbos whirr

Thanks very much to all who were so helpful. I think I will be able to get the job done now. i'll leave a note here when the results are in and hope i find the original setting way out of whack. That, of course, will mean that we have made a big improvement on an, already ,fine car. Steve

Greetings Steve,

Congrats on your new purchase, hope you enjoy. If you are in need of the MB diesel manual instructions on drip timing, I can email the pics and instructions to you if you like. I think Bill pretty well covered it, but I too am having problems as well. I have the bent tube I got from performance parts, but following the directions in the manual still has me getting flow than it starts trickling down to just one more drip after that. I must be doing something wrong or am not reading between the lines in the manual.

Charles

Charles,
You seem to be doing the drip tube method the right way. As you approach the timing mark, fuel will flow from the overflow tube. When you reach the timing point, fuel flow will abrubtly stop. One drop should follow after about 3 seconds. Swivel the pump to get the correct timing.
This drip tube method is much more accurate than the ones posted above, and just about as easy. Set your timing by this method and you will never have to worry about the timing on your diesel. I have used this method on the many many MB diesel engines I have rebuilt. One thing that made it easier for me was that the engine was out of the car. Put the engine in the car, fill up the fuel filters and lines and start the engine. No need to bleed the lines. they are self-bleeding. That's what the rubber lines from nozzle to nozzle do. They Bleed the system.
Bill Lewallen Lexington, Ky. Where diesels purr and turbos whirr..

Greetings All,

Thanks Bill for telling me I was doing it right, and now I know why I probably wasn't getting the right response from the drip tube as I grew closer to 24 degrees BTDC. I tried setting the IP using the Baylor method just for S&G's I guess you could say, and found this out. The fuel would just begin to start pooling in the pipe thread housing at 10 degrees BTDC, 14 degrees advanced from where it should be. I adjusted the pump to it's max and gained another 5 degrees or 15 degrees BTDC I suppose on my next day off I will reconnect the drip tube and see where it actually is according to that method. Using the Baylor method I noticed several pluses in my favor after the adjustment. The first one and most noticable, hardly any black or blue smoke coming out of the tailpipe while it's running. Better pick up from a stand still, and fuel mileage made a 2 MPG jump to 26 MPG. What can I expect from the next 9 degrees of adjustment back to 24 degees, as factory spec? Will I start losing the little gained power I achieved, lose the non-smoking tail pipe or even greater power gain and fuel mileage? At this point I would have to believe that the pump was not set with aligning marks before it was installed and will have to be pulled, reset and then retimed. Any input on how easy or hard this may be, is welcomed. The manual makes it look pretty simple, simply remove, realign the marks and reinstall, retime start of delivery and go on your way. Can it be that simple?
If you know, don't keep the secret, share it with us all. It will definely show the importance of a well timed IP for the health of your Benz and wallet.

Thanks,

Charles

[Edited by can-do on 04-03-2001 at 08:38 PM]

Charles,
It will be interesting to hear how your timing checks out using the drip tube method. You may be close to the 24 degrees BTDC. I have seen MB diesels start and run fairly good at 18 degrees out of time, but they seem to fade out at around 60mph. Keep us posted on your progress.
Bill Lewallen Lexington,Ky.

Greetings Bill,

Initially, the pump was set at 10-12 degrees BTDC, and she seemed to blow blue smoke on start up, and after it was warmed up, it would puff black during idle speed. Now that I've kicked it back to 15 degrees, it blows a little blue smaoke on start up but goes right away after less than a minute, and doesn't puff black while idling. I was awfully surprised to see it even run at 10 degrees. My next day off is Tuesday, and hopefully weather permitting I can put the tube back on and relay to everyone, just how accurate the Baylor method was, and it will also tell me if I need to pull the IP to realign the timing marks. Is there any gaskets or seals I need to replace if I pull the IP from the engine? Performance wise right now, I have slow acceleration starting from a dead stop, unless of course I somewhat floor it. There seems to be a point of acceleration where it just takes off and goes though, generally after 50MPH at this point. The problem after the 60 MPH point doesn't exist right now. Actually, after 60 MPH it begs to be pushed up to 70 and beyond. It's my lower end acceleration that seems to be a problem, at least I think it's slow off the line. According to some specs I read from a link here on the forum it showed my TD wagon rate of acceleration to be some 20.3 seconds from 0-60 and I get that on my worst day with a 20 mile head wind. I think that one probably should be more like 15 seconds or so. The fuel consumption rate seems to be wrong as well, 23 MPG, get real, I get 26 now and the IP isn't even timed right. I was hoping to get closer to the 30 MPG than anything else.
Bill, I'd appreciate any input you may have on the removal precautions I need to take should I have to remove the IP to reset the aligning marks, as well as any replacemen gaskets etc. I need to get ordered now so I will be ready. Any other benefits I should see out of this beast when I get it timed out right?

Thanks,

Charles

Charles,
You are not going to like what I am about to tell you about getting your pump timed on the exact 24 degress BTDC. From what you have described, your injection pump is badly out of time.
To do the timing the correct way, the pump will have to come off. And that means the oil filter cannister will have to be removed in order to make room for the pump to move to the rear enough to get the pump off.
To reinstall, set the toothed drive so the missing tooth lines up with the mark on the pump. Snug the nuts up that hold the pump on,but don't tighten them. You might need to remove the pump and reallign it.
Now you can do the drip timing.Once Your are on 24degress BTDC, tighten all nuts holding the pump on.
If everything else on your engine are up to specs, your car will start much better,run better and smoke very little.
One other thing. Make sure you are on the compression stroke of number one cylinder when timing the pump.
Bill Lewallen Lexington,Ky.

Charles,
I forgot one other thing. There is a paper gasket between the pump and the engine block. You can easly cut one from gasket material.That's all.
Bill Lewallen Lexington,Ky.

Greetings Bill,

Didn't figure I could do the IP removal without the oil filter housing in place, but you gotta do what you gotta do. Doesn't look like that big of a problem at any rate. Should basically set the dampner housing to the correct 24 degrees before removing IP and reset teeth on IP pump and then reinstall and everything should be quite close to timing. Re drip test pump and tighten bolts. Nothing that a few three hours probably can't fix. I can replace that leaky shut off vacuum valve while I have the IP off.

Thanks Bill,

Charles

Greetings All,

I make this post for all that tread the dreaded drip tube method of injection timing, and will explain it so as to make it easy for the rest of you scratching your heads. Because I first tried the drip tube method without success, I resorted to the baylor method mentioned above, and saw my injection timing to be off by some 13 degrees. I reset the IP to achieve at best a 15 degree before TDC. Most of my black smoke went away and the blue during start up went away as well. I also gain top end performance, but seemed sluggish from a dead stop. I pulled the IP from the engine and reset the start of delivery line up marks while the engine crank was set to 24 degrees. From the looks of it, the original was off about two teeth, which must have made a difference when trying to set the start of delivery.
For the DIY'er to set the start of delivery do the following. Remove the injector lines, from injectors and pump fittings. Turn the engine over by hand, cresent wrench on power steering pump bolt or crank bolt, toward you, or clockwise, watch fuel as it spits from IP connectors pipes. Disconnect the vacuum line off your shut off valve, and depending on your IP, wire your throttle full open. Remove the pipe connector from the no.1 pipe and remove the valve and spring, thread the connector back into the IP and connect your drip tube to the connector end. Rotate engine in clockwise direction using hand method, and after the no. three IP connector spits fuel, look at your dampner as you turn it slowly, stop when you get to 24 degrees on a 300 non turbo at least that is. Loosen the three nuts on the front of the IP and one bolt on the rear, but do not move pump at this point. Using your primer pump stroke it until fuel comes out of the drip tube. If no fuel flow, or it flows freely, adjustment is needed. If it's not flowing at all, you need to slightly move the IP toward the engine, probably only slightly while pumping the primer until fuel starts flowing, and backing off till it stops, and releases a drop about three to four seconds later. This is your start of delivery, so lock down the holding bolts to your pump without moving it further. Recheck to insure you didn't screw up. If you are getting too much flow, and it doesn't stop, then pull the pump slowly away from the engine while pumping the primer, until it just stops and a drop follows three to four seconds afterwards. Lock down the pump at this time. If you get nothing either way you move the pump, or a steady flow in either direction, you will have to do what I did, and remove the IP and rest the timing alignment marks on the pump itself. If you find yourself in this pickle, please email me, and I will go into detail as to what you'll need before attempting this. If you managed to get this all accomplished, and you have your pump timed as the directions above, you'll have to fight a little bit with the injector lines to get them all to fit because you moved the pump from it's original position. It's really not a big deal for us real dedicated mechanics, DIY'ers that is. Any questions please email Bill, no just kidding. Send me an email, I'll walk you through it. Reading the manual leaves too many holes as to how it should all take place. I found myself scratching my head, but managed to figure out the missing words between the lines. Good Luck, I did find a performance gain on low end starting out and top end acceleration after this proper procedure, it also improved overall MPG of fuel burned, so it may help you as well.

Charles

[Edited by can-do on 04-13-2001 at 01:44 AM]