IP timing---"one drop per second"
 

I've gone through the process of setting the crankshaft at 25 deg. BTDC, making sure I am on #1 compression stroke, #1 valves are pointing up in V position, remove all the injector lines, remove spring & valve from #1 injector on pump, install drip tool, wire the throttle full open, remove the vacuum line to the canister on the back of the IP, (don't know what that thing is called), loosen 3 nuts & 1 bolt on IP, pump the IP pump. I get full flow, no bubbles and the flow lasts several seconds and starts to drip but it finally slows down and stops. Never getting the constant "one drop per second". I move the IP forward and backwards in all possible positions and not achieving the "one drop per second".

Am I suppose to be looking for a constant one drop per second? Does it sit there and drop one at a time for a long period of time? Do I pump more than one time? I get a full flow pumping just once.

Thanks,

JFC

your close enough just tweak the crank one way or the other.a hairs width :)

vent the fuel secondary fuel filter
 

you need to mention which car you are working on.
i never tried it but i suppose if you didnt open up the fuel line at the top of the filter it may not let the fuel flow correcty while setting the ip timming.
also mention what all you have repaired and why you are setting the ip timming.
larry perkins
72 old cars

I recall moving the IP in towards the block advances timing, out retards.

If you aren't finding any location which caused fuel to stop flowing when pumping, then something is seriously wrong. Bring the crank around again twice to the right position and check again after setting the IP with one of your old injector pipes. (Back to original IP timing.) Make sure the timing chain stays tight-no back sliding. Check with the pump as you approach (and pass) 25 degrees on the crank. I think Pindelski is right on this- better to remove the fan and shroud so you can then easily crank from the top.

Drip is to hard- find the position which JUST stops the flow.

Did you just replace the timing chain or do something which might mess up your IP timing badly?

Bruce McCreary
(2) '85 300Ds, 83 300CD

I had a lot of trouble "seeing" the 1 drop per second when the throttle was full open. It worked well for me at the idle position. Maybe it's just me, and I know what the instructions read, but that was my experience. Maybe this would be easier with 2 people. one underneath on the crank and a second on the primer pump watching for the transition to drip.

Its a tricky procedure the first time you do it...
 

Please make sure you read the instructions carefully.
The Black Haynes manual describes it very well , so use that if you think you are missing information.
I have done it some 12 to 20 times and I still make a mistake once in a while. That drop will come if you are set up correctly.
When you finally get it scribe a match mark on the pump and the engine to show the correct position, in case you ever pull the pump. Also dont loosen the pump too much or when you bolt it down after you set the timing it may change position.
I remember once I was so intent on getting it 100% right, I did it 5 or 6 more times using the reference scribe mark I made to "fine tune" it. I wanted that engine set dead perfect.

I worry that the pump method provides a decreasing pressure... which may not allow you enough time to move the IP to the proper place...
When TCane did mine we used a fuel container placed above the IP so that the pressure was constant and we had plenty of time..... mine was pretty hard to move... he did not remove the steel tubes... so some brute force was necessary....

IP timing
 

Thanks to all who have responded.

This is my first experience owning and working on a diesel. The car is an MB 77 300D. This is an engine swap. I do have a friend, mechanic but not diesel menhanic helping me. I am using the Haynes Manual which is a pretty good manual. I have followed the instructions to the T from the manual and I couldn't get the one drop per second thing so we got it as close as possible and buttoned things up, started the engine. We used ether mist over the intake manifold opening and kept doing that a little at a time until the engine smoothed out (instructions from the archives). It didn't smoke. The throttle is very slow to respond. We drove it and went from 0 to 60 in about a minute. Just no power.

Now I really need help.............

When we took the engine out, we failed to mark the vacuum lines that go to the IP, under the dash, to the ignition, etc. I don't have them hooked up. I was reading the thread posted by Phantom showing the vacuum diagrams but there was none for a 77 300D. Reading the archives someone said it didn't matter if they were disconnected. Don't know if that is making this engine powerless or what. I'm not able to shut off the engine with the key.

When we were adjusting the valves, my son mentioned as he was turning the engine over, that it felt as if there was a lot of compression. So I'm assuming the rings and valves are in good shape. The engine we installed has 212K on it. We did install new rod and main bearings.

So we decided to go back to the IP timing again and see if we could get the "one drop per second" done up right. And therefore I will ask again:

When I find the spot where I am getting good full flow, no air, and it begins to slow to dripping, am I suppose to be looking for a constant one drop per second? Does it sit there and drop one drop per second at a time for a long period of time? And if that is the case I should be right on time. Right?

I know the timing is critical as is an all engines. Therefore, I appreciate all the help with this project. I also desperately need help with the vacuum lines. I've raised several hoods on 77's--81's looking for one that is hooked up right to no avail.

Thanks again,

JFC

I need to try this.
Does anyone besides MB sell this drip tool?

Danny

Ebay has them all the time.........

James, the dripping is roughly one per second, but fuel temp and surface and size at tube outlet will come into play. The transition from full flow to dripping to stopped happened to me within a VERY short amount of rotation - like 1 degree. It's so short that it's real easy to go by it, but once you hit it you know you are right there. Sort of like riding a bike :)

What your trying to find is the period just before the lift plunger closes off the plunger housing to start squeezing the fuel towards the injectors.

Did you take out the element spring and plunger under the pump top element
before refitting the element ?

I would continue turning the engine towards TDC( And past, if necessary.) untill the flow stops (While someone pumps the lift pump for you.)

The test is supposed to be done with a special column of diesel to get constant head pressure.

What you can do instead (if you have a sedan, at least) is fill the fuel tank and get the back of the car up on ramps or jackstands. Then you won't have to pump by hand.

Ted

ip timming
 

from my observation of the ip drip method i think the mb engineers wanted you to use the column of oil in the fuel filter because its mount is fixed and the drip tube is a fixed height when turned toward the block.all you are doing is setting the gap of the power piston just before it rises to its cylinder bore which starts the high pressure cycle and allows no more fuel to enter.if you use a higher fuel level than the top of the oil filter to set the one drop per sec then you timming will be set fast as the higher fuel level will push more fuel thru and you will have to speed up the pump setting to get the one per sec. lower the fuel level and your timming will be slow. just adding my opinion as i observed the total system.
larry perkins
72 old cars

"from my observation of the ip drip method i think the mb engineers wanted you to use the column of oil in the fuel filter"

But doesn't the filter feed from the top ? Does it say anything about opening up the other side so that vacuum is not keeping that fuel from flowing to the IP as its constant source ? Seems that would not provide enough pressure... it would be more like syphoning.... but with too much constriction behind it... ?

Someone needs to try just putting a fuel source a couple of feet above the IP and setting it... then see if it runs OK...