A couple of starting issues

[aeonflux]

Still struggling to get my '75 240D starting properly, and was checking to see if anyone has had similar problems. I have two issues that I am not sure are related:

1. The car begrudgingly started before I swapped out the fuel injectors. It started three times after the swap, and when it is running, it runs better than ever. Good idle, no smoke, better acceleration, no stalling. The problem is it won't start. When I crank it now, I don't hear fuel delivery.

2. Before I changed the injectors, it would start sometimes, but the battery would lose charge after 30 sec or so and after that would need to be jumped. It still does this after the injector change, which I new it would, but I can't even jump it now.
Batt tested good
Starter rebuilt
Alternator tested good
Battery at 13.05 volts off, drops to 12.10 volts while the glow plug light is on, and rises to 12.55 volts after relay clicks off. 12.10 and 12.55 too low to get starter moving.

This girl won't let me rest. Just one month of worry free driving, start small right?
Thanks again for any insights. This site has been a lifesaver.

Dave

[kerry]

Do you have OE loop plugs or retrofitted pencil plugs? Have you confirmed they are all functioning.?

[Brian Carlton]

When were the valves last adjusted?

[aeonflux]

Hi, thanks for the replies.
The car has the new pencil style glow plugs with the bosch fast glow plug relay. I tested the glow plugs two months ago and they seemed fine(ohm resistance ok and got red hot when hooked to jumper cable.)
I adjusted the valves 2 weeks ago, just before replacing the fuel injectors. It didn't help the car start/run better, but the p.o. mentioned he had recently adjusted them. I checked them just in case, and because I had never done it before and wanted to try.
Is it normal for the battery voltage to drop to 12.10 volts while the glow plug relay is operating, and then rise when it clicks off? From reading other posts here, it seems like 12.10 wouldn't be enough to turn the starter fast enough.
The reason I think I may have a fuel issue as well is before I replaced the injectors, I used to here a spraying/sputtering sound as the starter turned, and if I pressed the throttle it would start. Now I don't.
Thanks again for any insights. I'll keep searching here as well.

[Diesel911]

Glow Plugs can go bad anytime; tow months ago was two months ago.

I cannot hear my Injectors spraying and I have never read of anyone else who can; so I do not know what to make of that.

A compression Check while the Injectors were out might have been revealing.

Does your Fuel Injection Pump have a Pneumatic or Mechanical Governor?

If it is a Pneumatic one you will have a hose or tubing going from the Intake Manifold to the upper rear of the Fuel Injection Pump and a Butterfly Valve in the Intake Manifold.

When it does start what type smoke does it have at the Tail Pipe.

[Paulc66t]

Check that you have a good ground connections from battery to frame & Battery to engine block/starter. Use a multimeter and measure the resistance.

[aeonflux]

Originally Posted by Diesel911

Glow Plugs can go bad anytime; tow months ago was two months ago.

Does your Fuel Injection Pump have a Pneumatic or Mechanical Governor?

When it does start what type smoke does it have at the Tail Pipe.

As for the glowplugs, this starting issue was happening two months ago, which is why I checked the glow plugs then. I checked my IP and it is pneumatic. As for smoke, not much at all, a little black when I rev(revved) it high at startup.

Paul, I cleaned the ground connections at the battery/chassis, and the starter/chassis as well. I also replaced battery/starter cable because it was bad. I have a meter, do you know how to check the resistance? This could be part of the problem, because back when it would jump, when hooked to another vehicle the starter would crank super quick, so maybe I was getting ground from the other car.

Thanks, Dave.

[Diesel911]

It is the very last thing to check due to the cost. But, the Diaphragm on the Pneumatic Governors is made of what I have been told is Oiled Goatskin.

When they get old the become less flexible.

Also there is a small Hole somewhere on the Governor that exposes the Diaphragm to the atmosphere. If that hole is restricted by corrosion of the Aluminum the Governor may not act right.
However I am not sure if it would influance the starting amout of Fuel or not. Maybe the guys on the Classic part of the forum would would know.

Have you loosend the Hard Line Nuts at the Injectors and had some one crank for you to see what type of Fuel amount is coming out?

Maybe you are having a Lift/Fuel Supply Pump pressure issue due to the Fuel Supply Pump or the Fuel Injection Pump Relief/Overflow Valve that is not allowing enough fill pressure.

[aeonflux]

Thanks Diesel 911 for the suggestions. I did a couple of things that helped it actually start, but it still needs some help.
I stretched the spring in the banjo fitting at the back of the IP. Sources here say 27mm is correct, mine was only 22, so I stretched it to 25, 27 seemed way to long for this spring.
I checked the tank strainer, looked clean, like new.
Tightened all fuel clamps.
I also replaced the hand pump, which I think was introducing air into the system.
I think my big problem is air in the fuel system. The primary fuel filter is barely half full with fuel. I ordered new seals for the delivery valves, some of which are leaking, perhaps that is where air is getting in.
I'll check the pneum. gov. like you suggested and I am getting fuel to all the injectors, as for the amount, I am not sure how to gauge it. definitely a steady dribble. Thanks again, Dave

[tangofox007]

Originally Posted by aeonflux

The problem is it won't start. When I crank it now, I don't hear fuel delivery.

Have you tried pressing the accelerator pedal slightly while cranking?

[aeonflux]

Thanks everyone for the posts and advice. The problem ended up being air in the fuel lines. Once I replaced the hand pump, delivery valve seals and tightened all the line clamps and bled everything, the car fired right up. What was happening was the battery would die before it would force enough air through the lines to turn over. Is it normal for the batteries on old diesels to run down so quickly? Seems like 30 seconds of cranking and its near dead, while any gasser I've ever owned would crank for at least 90 sec before it drained.

Thanks again! Dave

[Rafi]

do you have the right size battery ? size 49, 14" long

[Brian Carlton]

Originally Posted by aeonflux

Is it normal for the batteries on old diesels to run down so quickly? Seems like 30 seconds of cranking and its near dead, while any gasser I've ever owned would crank for at least 90 sec before it drained.

Thanks again! Dave

It is normal for old batteries on diesels to run down relatively quickly.

A good battery will crank for 30 seconds steady with almost no drop in cranking speed. With a short break, you can certainly get two more 30 second rounds as well.

[barry123400]

When you mentioned using a jumper battery the starter revolutions where much higher. Yet your resting voltage indicated the battery in the car was fully charged. Other than cleaning the battery posts and the battery cable clamps. You might really benifit from a new battery.

I would still have the old battery checked again first but think it is tired from your description. Also what is the charging voltage across the battery terminals at idle. Being a diesel it is much more willing to start quicker at higher starter revolutions.

Glad it was not a case of marginal cylinder compression.