Injector pump problems - PeachParts Mercedes-Benz Forum

#1 10-22-2004, 05:01 PM

Well, I tried to replace the IP on my 69 220d. Bought one from someone who "said" in was taken off a running car that ran great.

My car idled very high, and I checked and double checked everything, so I figured it must be the IP.

I took my old one off, and put the new one on, but, didn't remember that I had to make sure the timing was the same, of which would be about impossible to do.

I then took the new one off because I followed the books instructions exactly to try to do the drip test.........got nothing.

I tried to use LP air into the "in" port but never got anything to come out of any of the ports even after turning the IP shaft about 20 times.

I then did the same air test with the old one, and I got air to come out of the #1 line all of the time and it never stopped.

I figured I could just take the pump off, use the air test to get it set to where the air just stops coming out, then set the car to 24 BTDC and put it back in, but evidentally not...........

Anyone got any pointers or help with this situation?

psfred · #2 10-22-2004, 10:00 PM

Guess and b'God only works for lucky people, and I an't lucky...

Set engine on compression stroke of #1 cylinder (both valves closed or closing, both lobes pointing up) at 24 BTDC.

Look at the front of the IP. There is a mark at the upper left corner, a "missing" spline on the coupler splines, and a mark on the shaft. Line these up and install so that be bolts are in the middle of the cutouts on the mount. This should get you very close. Leave the nuts loose so you can move the pump back and forth.

Make sure there is a coupling sleeve between the intermediate shaft and the IP, too, else it won't turn.

Next, either obtain a drip tube or make one from plastic hose of some sort -- it only needs to push over the injection line fitting and seal with the free end bent over so you can see fuel drip off. Remove the #1 (front) pressure valve holder and carefully remove the spring and little steel valve from inside and screw the pressure valve holder back on.

Wire the pump linkage at wide open throttle. Pump the hand pump to fill the IP with fuel. If it's set right, only a slow drop by drop flow will come out of the drip tube. You may need to crack the bleed screw on the top of the pump next to the oil filler cap to bleed the air out. Tighten it when no more air comes out, only fuel.

Check that you are still at 24 BTDC on the crank, compression stroke of #1, then while still pumping, rotate the pump slowly away from the block until the fuel flows freely out the drip tube. Slowly rotate it back toward the block until the fuel flow abruptly slows down. It's obvious, but you can do it several times if you want. Just make sure the paper gasket for the IP doesn't tear or you get an intractable oil leak.

When satisfied that you have the pump set to just stop the flow (you still get a drip a second or so), tighten the mounting bolts, re-installl the pressure valve and spring, and the injection lines. Tighten the pressure valve holder to 25 ft/lbs three times, or it won't seal properly.

Leave the lines loose at the injectors, then crank the engine until no more air comes out the loose lines. Tighten injectors, run the glow plugs, and start it. May take a while, but it will start.

I'd personally check the chain stretch first, as a worn chain will have to be replaced and you would then need to rest th injection timing again. Just as easy to do it first.

Peter

#3 10-23-2004, 07:48 AM

Thanks!

I will give it a try this weekend. I saw the "split" in the splines on the IP, didn't know if it was an alignment tool or not though.

psfred · #4 10-23-2004, 11:43 AM

There is a mark on the flange surrounding the spline next to one of the screws.

Good luck!

Peter

#5 10-24-2004, 07:08 PM

Well, followed the instructions to the letter, but still nothing.

I took the cam cover off, rotated the engine to 24 BTDC, cam lobes were positioned up.

Removed IP and rotated the shaft until the "split" was inline with the mark on the flange. It didn't line up perfectly on the mark, about 1/8" off, but I figured that was adjustment range.

Put everything together, and.................turns over great but still not starting.

I pulled the one line off, and I am getting flow.

I am thinking I will just have my wife pull me w/ the truck and put it in 2nd and pull it till it starts.

It ran before I pulled the IP out (although 4 months ago). So, I figure it should be starting now, even if it is misaligned, it should still start.

Anything new to try Peter?

psfred · #6 10-24-2004, 07:51 PM

Do you have while smoke coming out the exhaust? If not, you aren't injecting yet, it can take a while to completely prime the pump.

If you are, I suspect you are still too far off. Just close won't work, you actually have to set the timing to the mark or it won't start after sitting for a couple months.

Make up a drip tube -- rubber fuel line will work, just cut the free end off so that it forms a point for the fuel to drip off (bottom side) and set the timing dead on 24 BTDC -- you may need to remove the injection lines to be able to rotate the pump. I know this is a hassle, but it ain't gonna start until the pump timing is correct.

1/8" off is probably ten degrees or more, and I'd bet it was late rather than fast, too!

Peter

#7 10-25-2004, 11:50 AM

No smoke at all was coming out, didn't give the hint that it wanted to start, just cranked over.

I know the pump was primed as I pulled one of the lines off, and checked it, and it did have the drop of fuel come out as it was turning over.

I made a drip tube from an old line. It just requires removing the spring from underneath where the line screws onto right? Then just put the "bushing" that you screw the line onto back on with not spring and valve right?

It isn't that bad it only takes about 10 minutes to get the lines off and valve cover back off, so it should be pretty easy. I think the hardest part is getting the rubber line back onto the fuel inlet to go into the IP for the fuel bottle to supply the fuel into the IP.

Have duty today, so will give it a shot tomorrow afternoon when I get home.

Thanks for your help!

Russ

psfred · #8 10-25-2004, 08:35 PM

Couple things here --

First, you must remove the little steel insert under the spring, too. don't lose it!

Second, verify that you have the IP full of fuel. There is a bleed screw next to the oil filler cap (the red thing that has 'Oel" on it). crack this while pumping the hand pump until all the air comes out, then tighten back down. It can take a while to get all the air out of the pump and get up to injector opening pressure.

finally, are you sure the coupling is installed? It's a hollow tube with internal splines that connects the IP and the auxillary shaft, and without it the IP isn't turning.

Peter

#9 10-25-2004, 11:21 PM

Yes, absolutely sure the coupler is installed, heck, I don't think the pump would even go on even remotely snugly if that wasn't there to "snug" it up into the opening.

I know it was working someone correctly as I removed the #1 line and cranked it over and had the flow come out of it every time it rotated past the #1 port.

I know it is full and pressured as when I pump it, I get a shot of diesel coming out the top of the main filter about 3 feet high! Damn near got me in the eye the first time when I wasn't expecting it to come out so fast.

I am quite sure that this final step should work, can't really see why it would be anything else. It is killing me not to be driving this thing!

Thanks

HGV · #10 10-25-2004, 11:32 PM

Couple things to do. Remove the injector. Make sure youhave the heat shields to replace them. Have someone pull the starter and energize the glow plugs. Look in the injector ports in the head and make sure all the glow plugs glow. Correct as appropriate. With the glow plugs out, crank the engine until you get a good flow of fuel out of each of the injector lines. Best to put a rag under the lines to make sure you don;t end up with a big mess. You should see a difiniantive pulse of fuel out of all injectors lines. Next do the driptest out of the number 1 cylinder as PSfred sugests. Then when the timing is correct, install the injectors. Witht he number one injector line in place, crank the engine until it has fuel in it. Then install allthe injector lines and try to start the engine. Hopefully this will get the car to start. Towing the car with the IP out of timing will not get the car to start.

Good luck.

Henry

psfred · #11 10-25-2004, 11:42 PM

Did you remove the pressure valve holders to change the o-rings?

Peter

#12 10-26-2004, 07:35 PM

Ok, here goes........

Lined up the IP marks as you said, and the crank to 24 BTDC.........then did drip test.........test showed that the IP was stopping flow at about 5 BTDC.

I then set crank at 30 BTDC, then set marks on IP again, did drip test, slightly out, then loosened 13 mm nuts, made slight adjustment, did drip test 3 X's...........have you heard the term "Balls on?" Well, now it is.

Put everything back together, primed pump, cranked nothing...............................battery too low.

Pulled my tahoe next, to it, jumped it.....................5 minutes, it is running.

Now I make my final tweaks to the idle. Finally it is idling the way it was supposed to.........slowly, man it is nice now, not idling at a traffic light at about 2000 RPM, now it seems to be a steady 700 or so, have to get my light out at look at it, and get it set. Seems to be holding the oil pressure at about 37 - 38 #'s idling and that seems to be best by ear anyway.

Thanks for all the help Peter, the help with the marks on the IP put me over.
I appreciate it!

psfred · #13 10-27-2004, 12:06 AM

No problem, I've been helped out many times before myself!

It's pretty easy once you know how it works, eh? Hopeless if you have to guess, like usual!

The pump tends to jump a spline or two when you install it, as there is no way to lock it, unlike the ones on the W124 and W201 (and later) cars. I've seen instructions that suggested moving a couple splines fast for this very reason, and I guess it's not a bad idea, will keep that in mind on the 220D (currently at 20 BTDC).

Glad it runs right -- sounds like the governor diaphram was leaking on the old one.

Peter

#14 10-27-2004, 09:34 AM

Yea, knowing is half the battle right? I know I've heard that somewhere before!

Actually I have no idea why it idled too high, but it had to be something with the IP. But it couldn't be the gov, because I took the old one off and put it on the new one, thinking that was why it wouldn't get going initially.

Heck, I think I have put more money into this thing than it is worth.

New IP (but it was cheap), new brake m/c, new clutch slave and m/c, rebuilt brakes, new injectors.

Then the last week I was driving it the radio stopped working, but it was the original, so I guess it lived a full life right?

I am very thankfull for the help, and hope I can be of help for someone else in the future.

psfred · #15 10-27-2004, 07:15 PM

The radios usually fail due to bad solder joints and can be repaired by simply resoldering any questionable joints, or can be rebuilt by Becker.

I'd question the value of doing so, the car is never gonna be worth much, but hey, it's your money!

Peter