Loosening the injector nuts does nothing to speed up starting. I've tried both ways and it purged/started just as fast either way. With vigorous pumping of the primer pump you can get the whole system bled in a few minutes.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Up to the IP, that's where the starter comes in handy.

__________________
83 SD

84 CD

Oh Ive pumped vigorously alright, Ive even traded off with my brother like a marathon. I'm also using a new Bosch primer pump and I dont know I would be able to feel any resistance as its spring loaded (as Diesel911 mentioned).

vstech thanks for the step by step.

One thing Im wondering about is when I pump the primer pump there seems to some resistance somewhere and by what Ive expiremented with (see my 1st post) it feels like its coming from somewhere before the primary filter as I see bubbles coming up in the translucent filter as Im pumping.

Not consistently but it seems like the pressure will build then a few bubbles will come.

Ive checked all the lined in the engine and all are new and tight. I havent checked the ones coming from and attached to the tank but would air bubbles show up in the primary filter all the way form there?

I havent mentioned I have a greasecar kit installed for WVO. However Ive bypassed it all to see if there would be a difference (perhaps a faulty switchover valve) and there wasnt.

I think Ill be trying the injector loosening nut techniqu as It one of the few things I havent tried.
vstech when you say to watch till there are no bubbles coming from the injectors will I be looking for foamy bubles or just bubles in the stream? I guess I should just try it to see what it looks like but I thought I would prepare myself to know what to expect when I go tomorrow to work on it again.

Thanks for all your input! this feels like I may be able to avoid the mechanic (I hope)
Michael

If I'm not mistaken, the FSM procedure says to pump the primer pump until you hear the bypass valve in the filter housing start working.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I may get flamed, but here is how I got the air out of my fuel lines after cleaning the tank screen and replacing the hand pump and filter. On my 1982 240 there is a fuel tank vent line that terminates by the left back wheel. It has a little bell shaped device with a one way valve in it, (check valve) clamped at the end. I easily removed the check valve and inserted an old valve stem from an old inner tube into the rubber hose. I reused the clamp from the check valve. Next I removed the gas cap and placed a thick plastic bag over the fuel opening, (ziplock)and replaced the gas cap. Now the tank is sealed. With a hand operated bicycle pump I pumped several times adding a couple of pounds of air pressure to the tank. I then went up to the filter and cracked open the banjo bolt exiting the filter. After a minute or so clean fuel flowed from the filter. I closed the bolt, released the air pressure, and I was able to start my car very easily. Afterward I removed the valve stem and replaced the check valve. On my car the check valve is located by the rear jack point. Once I found the check valve it only took 5 minutes to pressurise the tank. Don't put in too much pressure, you might blow up your tank. It only takes a little bit, just enought to force the fuel through the lines. Good Luck Dave

I think you win the prize for the Most Origional Method Catagory for your application of pressurizing the Tank!

Also you can upgrade the process. In all of my Cars I have a 12 Volt Electric Tire Inflation pump in the trunk. Harbor Freight sells them and Big Lots sells them. I have bought them for as low as $8 each.

Since they put out a low volume of air you would not have to worry about overpresurizing the Fuel Tank as the pressure would build up very slowly.

Of course those Pumps are also handy for their intended Tire inflation purpose.

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84 300D, 82 Volvo 244Gl Diesel

Sounds kind of fun, anyone know if theres one of these check valves on an 85 300TD wagon? Im not near the car right now. but will be there tomorrow.
Thanks again.
Ill let you all know how I manage.
Michael

I know my 84 300D has one. I would imagine all the W123 models would have it.

__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

The question about air bubbles appearing in the primary fuel filter has not really been addressed. That sure sounds like one or more leak points in the flexible or hard lines between the tank and the filter. The hard lines can develop leaks from abrasion or corrosion, and of course the flexible ones can just deteriorate. Needs to be looked into!!

__________________
1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

The bubbles are likely caused by too much air in the fuel tank. Some of that air needs to be displaced.

I suspect that most of the previously mentions "extreme' measures involving pressure and vacuum could be avoided if one thing was considered: fuel flows down hill. If the level of fuel in the tank is higher than the fuel pump, gravity will take care of the situation.

Especially in the TD since it's tank is mounted flat.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

For this to work I would Imagine the return line would have to be blocked so that pressure wouldnt be also building there thus just creating a "loop" of pressure? or pushing possible air back in from the return line?

It would make more sense to pressurize the return line (in the direction of the tank) and leave the vent line alone. The valve on the vent line will allow a slight amount of positive pressure in the tank while protecting the tank from excess pressure at the same time.

So I loosened the injector nuts, after purging the line leading to banjo bolt exiting filter, and once it spat out fuel form the injectors and a couple tries after that It caught and started up.

I also took off the return line from the tank and pressurised the tank with a bicycle pump although I dont think the filler cap was totally sealed so presure would lose fairly quickly.

It ran for about 5 minutes idling and I was proud and ready to pull out of the driveway when it stalled again.

I tried the injector lines again and I never did see fuel comming out again as I did the first time. I rigged up a more constant flow of air to the tank with an air comprssor set to 3 or 4 psi.

I waited till fuel came out of the banjo bolt exiting the filter and tightened it. I primed the pump till one could prime no more.

Probably 5 minuted of fast pumping and turned the key and it would just crank sometimes without even a sign of catching any fuel.

Eventually when I bled the line to the bolt again and tried again with the injectors, sometimes seeing bubbles come out when I loosen them but never seeing any fuel comming out when cranking for several minutes, It started again. Probably after 6 or seven more tries with varying pressure, pumping and nut removing and retightening, and about 3 hours later.

It started for longer and it Idles well while I cleaned up and I even had the balls to switch it to Veggie fuel. It ran just as smoothe for about 15 or 20 min.

then some slight hickuping, I went and stepped on the pedal and purged the lines with the auto purge system that sends diesel through alkl the lines again but befroe the 30 second purge was over it had stalled. and as I tried and tried again it got less and less smooth and eventually was just the battery cranking the starter and nothing else.

I made a mess of the driveway with all the fuel spurting out of the return line and I managed to switch the two lines which were old and crumbling while I was at it. But I dont want to get under there again and get full of fuel to stick a comressor in the line. I dont seem to have a check valve as was mentioned.
Could the injector pump be malfunctioning? or is that belt driven?

Any Ideas that would save me from swimming in Diesel again?
Thanks so much for all of your suggestions. It got me very close but I had to call it a night. I dont know whats going on.

I myself applied pressure to the tank in the manner I sugested. It is not some theory. I did not clamp the return line. I know nothing about the system being a closed loop. Air in the fuel line is released when the banjo bolt on the fuel filter is cracked open. I tried this method when I had trouble getting fuel to the filter after a fuel tank screen cleaning, hand pump replacement, and filter change. I suggested this method when Azitizz said that he had had similar troubles, and that no amount of pumping seemed to prime his engine. Try it, as long as you don't go overboard with the air pressure, what harm have you done. If it's going to work you should know very soon after you crack open the banjo bolt. Good Luck, Dave