W123 no start condition
 

#####Update 04/14/2020 the car is no longer smoking now as compared to before######
Last post for now has video of car
Good day!

I have recently acquired a W123, 1980. Towed home .

The engine cranks over just fine, I have pulled the number one and 4 glow plugs and they turn smoking hot as indicated by instrument light(all plugs are getting voltage installed on engine), the filters are full of fresh fuel ( tank was full at purchase) , the injector lines at injectors are seaping some fuel if I crack the nuts but return lines seam mostly dry.

There is no sign of smoke at tail pipe.

I have also verified the injection pump timing with spline on pump, 24° before top center and on the compression stroke verified by looking at the number one cylinder valve lash.

Fuel stop Pneumatic solenoid is releasing the rail inside the pump also.

I do not believe fuel is passing at a high enough pressure to the injectors where should I start as the I show fuel just recycles and appears to be returning when I run fuel off a small supply at injection pump and consolidated return line as if purging.

Mechanical lift and primer are fine and check valve there is working...

Wow, sounds like you already ticked off everything on the list.

With everything done so far, what are you getting? Any combustion at all?

Maybe pull injectors, install on fuel lines, crank and check for fuel spray from tips?

Thank you for recommending pulling an injector and checking for spray, I will do that tomorrow. When cranking a small squirt is coming out on the #1 line when fully removed from injector, all the diesels I’ve owned have just had fuel in air or clogged fuel lines from trash and not the case on this one.

I heard a couple tiny combustion’s today when spraying diesel compatible starting fluid in but I didn’t do that much since it’s not fixing anything.

Any idea when the last valve adjustment was done? You can loose compression if they are to tight.

No smoke is not a good sign.

If you know where the fuel pressure relief/overflow valve (it controls the fuel supply pressure) is if it is the kind that can be taken apart you can remove the spring and the ball bearing that is used for the valve. Check the free length of the spring is 27mm. If not gently stretch it until you get a free length of 27mm and re-assemble it.

Re-prime with the hand primer. If the Hand Primer has ah had plastic know on it (usually white) those old hand primers generally become a source of an air leak.

This won't tell you if the Fuel Injection pump is timed correctly but remove the Fuel Injection hard lines entirely from the engine and after you primed with the Hand Primer crank the Engine with the Throttle Lever in full fuel.
You should see fuel spout out at least an inch or 2 from the Fuel Injection pump.
If it is not doing that then there is likely something inside of the Fuel Injection pump blocked. However, If on the top of the Fuel injection Pump you have a row on each side of 13mm nuts don't touch those as loosening them changes the fuel amount on each of those individual elements.

The attached thumbnail points to where the Fuel Pressure Relief/Overflow Valve is.

I have MB dealership records from within 20 years ago and Compression feels good looking at other valves after removing valve cover today

So I haven’t touched the other 13mm nuts so no worries there, I was unaware of this relief valve ! I think it is defiantly allowing fuel dump so first thing I will check tomorrow!

No problem!

You have combustion, so there is compression, sounds like a fuel issue?

So that's where the fuel pressure relief valve is, didnt know that. Definitely one place to check too.

Oh, thanks Diesel911 for showing us where that was

It is OK to use the Block Heater to warm the Coolant up and you can cycle the Glow Plugs on a couple of times but just before using the Starting Fluid unplug one of the Glow Plug Connectors at the Glow Plug Relay. That way you won't get any premature ignition. It allows you to control how much Fluid is used and avoid having some large gulp of the stuff suddenly hitting the Engine.

When you use the Starting Fluid have someone else sit in the Car and to the cranking while you spray the Starting Fluid. That way you wont overdoes it. Of course you only spray while the engine is cranking. I have seen my Boss back when I used to work in a diesel fuel injection shop do this many times.

At the shop they occasionally would send me out to customers vehicles. I have twice come found Engines that would not start with Starter Fluid. If they won't it is an indication that the compression is too low. Stuck piston rings can cause low compression.

Just taking a stab, but was it run on used Friday night all you can eat fish fry oil?Could be as stated passing some fuel from IP but not at sufficient pressure to pop the injectors. Try the block heater for an hour or so and maybe a little heat from a heat gun on injectors.

As of today/ Friday :

Def no indication of veg oil ran in it in it.

So today I pulled off one injector then reconnected externally on a hard line it and it appears to be in good shape but when the engine cranks there is definitely no fuel coming out of it.

A pressure relief valve spring was three eights of an inch out of link and I did fix that this morning first but you did not take care of the engine no start issue.

I do you now believe that I’m getting air in the lines when I have the hard line fully removed off the injector housing there are some tiny bubbles showing up. I believe I have a newer style Bosch hand pump so I don’t think that’s the issue and I submerged the banjo bolt that goes into the injector pump side in a container of diesel and saw no bubbles?!?!?
Suggestions so very much appreciated

Primer pump good style?

Good method to find air into fuel line?

Try cranking without the fuel cap on. I doubt that is the issue but cost zero and takes a few seconds. Or fab up a small fuel tank in the engine bay, gatorade bottle or so. Many links here. That will isolate the air in the fuel line problem to the last few feet of lines.

Not sure where your located, but here in the midwest I have had two w123s that the supply fuel line corroded in the same place. under the driver side rear door, at one of the supports for fuel system.

I tried the fuel cap thing, I began replacing all flex fuel lines in the engine compartment area this evening but closing parts store had no hose clamps.

This was a California car until 2000 then went to Seattle last 5 years so less than Indiana! But will still check external lines tomorrow.

I’m down in Olympia WA, wish I was up near Kent!