Howdy,

First my 300D is definately getting between 26 and 27 MPG......

I drove to town today, and this thread popped into my head.....began thinking about LATE timing......we really can't gather enough info with the instrumentation on our carz....on my ship's engines I would know each cylinder's cooling (jacket) water temp in and out, Exhaust Temp, nozzle (injector) cooling water temp in and out, piston cooling water temp in and out (yup we had water cooled pistons), fuel temp, and had an indicator cock that we could attach an instrument to and find out compression and firing pressures.....and pull an out of phase indicator card and see what the pressure was inside of the cylinder as it fired and moved thru it's stroke.....however I got to thinking, if the injection timing was a tad late, the fuel would be burning a bit further after TDC....and thus not create as much HP....so it would require more fuel to develop the same power......

A bum injector can/will do many things.....it all depends on what it's doing....it generally shows up as inefficiently burned fuel...black smoke....and sometimes as a loud knock....with these little diesels, I don't have a clue....if you really suspect the injectors...get the other set, have them tested and set.....then swap them with the originals.....and then have those tested if ya really wanna know......

If the car is running smoothly, I doubt it's your IP...unless it's out of time....or really trashed.....you can also take the IP to the Injection Shop and have it put on a calibration stand.....ask if you can watch.....it will tell you exactly how much fuel is pumped for each stroke.....actually 1000 strokes..and you divide it out......you will see the actual fuel pumped in 5 graduated cylinders.....and will instantly know if one or more are not working up to par......I have already written way too much....It would be difficult to explain hoe an injector's plunger's helix works within the barrel here.....

Sorry, I got carried away......but if you're interested I could recommend some books that you may possibly find at a library.....

SB

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Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Carrameow....how many miles do you think are on the "new engine" and the injectors? A couple hundred thousand miles on thoughs injectors is nothing unless the engine was totally neglected.
I would do a valve adjustment first.....I know you don't want to hear about adjusting anything but it does not cost anything just time. A simple Valve Adjustment can breath new life into an engine...can restore like new performance and economy if the engine is in good running order.

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FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

Yes, I did the valves also, the IP, the chain, and with EGG on my face I think I found the problem...a fuel system leak that didnt show readily because of the heavy rain we've been having in NJ the last week...I won't know for sure until tomorrow..

G'mornin',

Am glad that you found that leak......

SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Thanks Shorebilly.
I Just took my 60 mile drive in to work. I had removed the feed and return line under the floorboards back when I was welding in new floorboards prior to my paint job and I remember I was in a rush.
I could tell the mileage is okay because the fuel gauge didnt budge an iota and recently I was getting some movement. Also I think one of my rubber lines was leaking. I also had bent/misadjusted linkage problems
Boy the engine sure is quiet!
Finally everything is back to normal and with the new chain and valve adjustment and ip retiming I get a big smile listening to her at the stop light. When I did the valves they were really out of whack especially the exhaust valves, I couldnt get a .030 or .035 feeler gauge under there. The ip was way off too.

I was and still am tempted to pass this one up. Seems to be something you know about the car that is not mentioned. It may be in your subconcious with lots of experience. Or it may not exist at all. At a twenty five percent or more decline from normal average fuel milage there should be a clue. Have you really made sure car is not dumping fuel at speed. Might not hurt to bring engine up to mid speed in your driveway for a minute and have a careful look for any fuel drips on the ground. It might not leak at idle. Disable the egr valve and make sure it is closed up as well. Probably done already. Number one element on any older pump is the most likely to be off if any element is. The result of too much aggression or not using common sense for timing attempts in the distant past for example. Does car feel normally peppy compared to other examples you have driven? Idle better, average or worse than other 617 engines you are familar with? No I do not disagree with your thought it might be the injectors or pump either. Or an amalgamation of many sub standard things. As for the injectors that have been out in the weather for a couple of months I just do not know. Oil would have been still in them and any water introduced by rainfall may have kind of homoginized with the existing oil. They might not be bad. If you can get them at a favorable price (nothing or near to it) why not give them a try. Nothing to loose but a little time and I can see no harm really. I suspect the approach you want to take is to narrow it down or find the problem by elimination. How does this engine start at cooler temperatures? This might provide the biggest clue or eliminate some things as well. For example an engine with severly retarded timing will be much harder starting I believe compared with cars of almost equal compression. In cases where I just do not know or have any pretty obvious prime suspects. Ocasionally a good tuneup sometimes reveals the problem or reduces the possibilities to more managable proportions. Make sure your return line to the tank is not obstructed as well.