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Pump Element: Don't Touch That Dial!
I don't want to.
BUT, it looks like the p.o. used some hokey-pokey copper washers, which are now seized in the bores of the pump elements. And leaking. I'm aware that the seals need to be fished out -- normally -- due to expansion from compression stresses. I typically carefully pry them out with a stainless dental pick. These are much worse than that. For clarity, here's the style of element/delivery valve arrangement I have on this MW pump. Valves are #50, washers are #47. #53 is pump element. #62 is a shim. The washers I'm considering R&R are swaged into the pump element counterbore so badly that I need to put them ON A MILL and machine them out for removal. Obviously, this will require that I remove, and restore the pump elements. As an aside, one also has a leaky o-ring. I'll replace them all "while I'm in there". I know, I know. This also means that I should send the pump out for alignment. BUT, this is my "go ahead. make my day" rusty, trusty winter beater. Our four lane city streets are down to 2.5 lanes with ice encroachment. It doesn't pay to park/drive anything you aren't ready to lose to a snow plow. A pump alignment will cost more than the car is worth, as my local bosch dealer can only tune Call it $1200 +-$1K. So. To the experts. There is no need to repeat the time-honored mantra "you could screw the pump, and the engine, beyond recognition!" I get that. On to the question of the day: Can I use the drip method, in sequence on each port, to tune the pump element positions? In other words: drip test to spec; pull #2; fix it; restore it; crank to 24d + offset where required. set element position to the measured drip rate; ibid #3, #4, and finally, #1. Repeat as required to get uniform readings. I'm posting this in the "less travelled" Perf Tuning board in the hopes of having hard-heads weigh in. The thread on glow plug "tuning" got me to thinking. I'm not convinced that a glow plug is linear enough to compete with an EGT sensor, but thats another matter enitrely. At a glance, the drip method would seem to be a technically sound predictor of "initial fuel rate" -- if carefully performed. I'm talking stopwatch, and perhaps a fuel pressure monitor. I'm not planning to change the shims, as I have no way to re-shim the pump elements correctly. However, the leaks are progressive, and bad enough that I can't get a drip test to accurately predict fuel rate anymore -- so I'm forced to do something before spring. Which ain't anywhere near Wisconsin. Weigh in, please. --frankb |
#2
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I assume this is for an OM617? If so, I have a good injection pump that I can sell you. PM if you are interested.
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1981 300 SD 213k miles "Stock for now" 1999 Super Duty 7.3L 113k miles 1981 300 SD 180k miles "Heavily modified" SOLD |
#3
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If you don't go the used pump route, I would very carefully mark the position of each element before removal. If you put each element back where it came from, along with the corresponding shims etc, and line it up, you shouldn't need a calibration...
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For Sale: 1982 MB 300TD 1995 Chevrolet Suburban 6.5TD Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel |
#4
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Find a used injection pump and replace your pump.
Don't even think for a second that anything you do can properly time it like a $100,000 bench machine. Its a RPITA to get them flowing evenly with a bench machine. Fractions of an inch make a significant difference. Last edited by ForcedInduction; 01-20-2009 at 03:27 PM. |
#5
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I am so going to prove you wrong one day FI.
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http://superturbodiesel.com/images/sig.04.10.jpg 1995 E420 Schwarz 1995 E300 Weiss #1987 300D Sturmmachine #1991 300D Nearly Perfect #1994 E320 Cabriolet #1995 E320 Touring #1985 300D Sedan OBK #42 |
#6
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I'll be too elderly to prove you wrong by then.
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#7
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Ummm .... and how does one validate that the pump elements on a used pump haven't been disturbed since last setup, exactly?
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However, that is not the question. I'll try to re-state it more clearly: On my 616, can I expect to restore its present performance by carefully aligning the elements using the drip method? Here's an observation: The Factory, in volume 1, suggests that one should check the drip on port #4, validating whether the pump needs service. So, if I check all four, and they are closely matched to an accurately projected set can I make the reverse inference --- plausibly infer that the pump can be restored to previous service levels?
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--frankb 1982 300TD 617.912 <NLA> . 1975 2002 E10-EFI . 1976 914c6 . 1983 MG LMIII <NLA>. 1988 Montero / 616<NLA> . 2001 TLS . 2005 Saab 9-5 Wagon |
#8
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Quote:
Quote:
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#9
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Your local Diesel injecton shop should be able to repair your pump. I was quoted "a couple hundred" for running mine across their BOSCH test bench.
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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver 1982 300SD - 232K miles - Wife's Daily Driver 1986 560SL - Wife's red speed machine |
#10
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the injection pump calibration i beleive measures the amount of fuel injected per cycle measured over many cycles and set to the spec.you could theoretically measure this on the car by collecting the fuel and comparing each element having run the engine for the same duration each time.the other spec would be the vertical position and travel of the individual plungers coming to engine tdc.probably best measured with a dial indicator.the adjustment process here would be shimming under each plunger.considering the precision requirements of these measurements and adjustments a fairly reasonable fee charged by a expert fuel injection for this service would seem to make sense
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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon |
#11
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It would if there was any structure to that paragraph!
Last edited by ForcedInduction; 01-24-2009 at 06:12 PM. |
#12
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sorry for the train of thoughts composition.
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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon |
#13
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Quote:
All the same parts (except for washers and seals) so nothing needs to be 'compensated for' or altered because of a change of part. Do each one in turn, setting the engine position for exactly 1 drip per second on the element to be worked on, and after re-fitting set again to exactly 1 drip per second...No Problem!- -OK, It aint gonna be as accurate as a Bench Test set up in accordance with the ISO Test-Plan, but better than pissing out valuable expensive fuel everywhere, and Infinitely Cheaper than a S/H Pump!! Naysayers are often brainwashed by gloom and doom stories/myths told by Fat-Cat Injection-Shops and 'idiot' mechanics....who have their own adjendas- -Why do you think the owners of such places all drive round in Jags!! (Because its a Rip-Off Trade, Has been for years!) Unless you Try, You'll Never know!!--If I was in the same position, I would do exactly as you plan. I have often repaired items including FI systems/pumps etc, that I have been told was impossible without 'special-tools/knowledge' but with a bit of planning and lateral thinking has all worked out..... If you have the time, parts/seals etc,-Go for it!!
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http://i190.photobucket.com/albums/z...0TDnoplate.jpg Alastair AKA H.C.II South Wales, U.K. based member W123, 1985 300TD Wagon, 256K, -Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog. W114, 1975 280E Custard Yellow, -Great above decks needs chassis welding--Really will do it this year.... |
#14
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you can get it within spec by hand. i have done it multiple times yes its not going to be friggen perfect but what do you expect from something thats free?
I say you do it and succeed.
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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac? As long as they would add one additional commandment for you to keep thy religion to thyself. George Carlin (Wonder where he is now..) 1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won. pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt. |
#15
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Just because you did it does not mean you should have done it in the first place.
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