Very Interesting Thread. I'm in the process of changing the glow plugs in my 240D and I figured I would attempt to do so with the injector hard lines in place, but decided other wise. The car has been sitting under cover over the winter and when I was working on it last it was 40F outside. The nuts on the hard lines are unwilling to budge, though I haven't used the breaker bar as of yet. I am curious though if I would be better off firing up the engine to warm it up before trying to remove the hard lines and glow plugs.

Would having the engine warm make removing these various items easier?

__________________
83' 240D 204,000 miles SVO conversion - Heated Pickup Stock Tank, 3 Gallon purge fuel tank, HOH, Coolant heated filter, FPHE, 2 Greasecar Valves. 12V pump for Veg. and stock pump for purge fuel. Injector overflow return to veg. tank.

98' VW TDI Jetta SVO Conversion 154,000 miles/57,000 WVO miles

This is rather interesting. So, if the delivery valve seals are not doing the job, the IP can't overcome the air in the hard lines?? Allowing the fuel to fill the hard lines by cracking them will overcome this issue??

What other symptoms are present with marginal delivery valve seals on the 617? The inability of starting the engine without cracking the injector lines should be a clue to other symptoms..........or not??

I would say that heat is always preferable. But, working around a hot engine is no fun at all. The nuts will "crack" loose if sufficient torque is applied. You probably should invest in a proper wrench for them..........an open end wrench won't do the job if they are overtightened.

I ended up replacing all 5 glow plugs with the hard lines in place. It was really easy with a box-end ratching wrench. I think removing the lines would have just added more time to the whole process. I did have to disconnect the throttle linkage, but that was super-easy, just remove the cotter pin and push the linkage out of the way.

__________________
==========================
Aaron
'84 300D 267,000 - Running WVO - Rice Bran Oil - Mmmmmm, fishy...
==========================

You must have hands like a mouse to get down between the hard lines......................I've removed two plugs with the hard lines in place............never again.

Hahah.. yeah. I used a tip I read on here or some Mercedes Help page where they suggest using a rubber hose to maneuver the new plug into place. I think I had to use that trick on a couple of the plugs.

Why did it feel like it took 5x as many turns to get the plugs out as it did to get them in? That was kinda weird.

__________________
==========================
Aaron
'84 300D 267,000 - Running WVO - Rice Bran Oil - Mmmmmm, fishy...
==========================

and when you stop it feels so good.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

the wd40 starting proceedure.

1. it is a method for priming a car that has lost prime. it is not useful in cold weather unless the above applies.
2. you need two people cause you must spray directly into the intake not though the air cleaner while the other person cranks the car.

hope this helps

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Possibly a situation occurs where the air is just being compressed? Seems to me I remember a few situations where cracking the injector nuts seemed to help certain individuals after repeated attempts. Coincidence? If the injectors do not pop open because the air colum has too much volume and does not reach pop pressure it just might create a stalled type of condition. Although one would think really good delivery valves would not let it occur. Perhaps some of our old pumps have more problems than we are aware of but still function reasonably well.

For the most part, I've gotten away without having to crack and bleed the lines to the injectors.

But there have been times when it just wouldn't work. So I cracked 2 or 3 lines just a little and cranked till I saw fuel. (This was on a non-powerstroke 7.3 Ford (International) V-8. I snugged the flare nuts back up and proceded on with the next 3 or so and then it lite up. Made a mess but fired up. I snugged up the loosened lines and let her run till it bled itself.

I believe it is true that you should not need to crack the lines to bleed air out but maybe we're talking about a tired injector pump or something like that.

Bottom line, I have had sucess getting diesels fired up by cracking the lines when nothing else worked.

Fluke? Maybe. But it worked.

Wayne