300SDL Resurrection - Page 9 - PeachParts Mercedes-Benz Forum

sixto · #**121** 03-22-2009, 11:05 PM

Define rich? In the absence of an air throttle, more fuel means more revs. If it's not revving higher than proper idle, it's not rich.

Sixto
87 300D

mplafleur · #**122** 03-22-2009, 11:52 PM

Quote:

Originally Posted by sixto

Define rich? In the absence of an air throttle, more fuel means more revs. If it's not revving higher than proper idle, it's not rich.

Sixto
87 300D

Rich as in huge amounts of grey-black diesel smelling smoke.

More fuel won't mean more revs if it doesn't get more air, does it?

Brian Carlton · #**123** 03-23-2009, 12:02 AM

Quote:

Originally Posted by mplafleur

Rich as in huge amounts of grey-black diesel smelling smoke.

More fuel won't mean more revs if it doesn't get more air, does it?

It gets all the air it can possibly use unless there is a severe intake restriction.

Heavy black smoke is unburnt fuel. What's the IP timing and the camshaft timing...........did you verify?

compu_85 · #**124** 03-23-2009, 03:09 AM

The air flow meter (not air mass, it can't tell temperature) has nothing to do with the running of the engine... it is only used to calculate EGR. You could leave it totally unplugged and the engine would run 100% fine.

Are you sure the injectors are sealing properly? There's no way it should have burnt through that much fuel under normal circumstances. I'd be careful, you don't want to melt a prechamber or piston!

-Jason

mplafleur · #**125** 03-23-2009, 06:25 AM

Only for EGR? What a waste of money. I'm putting a blocking plate on it anyway. You are right about air, just meter in the fuel and it will suck in the air needed. An engine is just a big air pump. I can remove the air filter, though it looks almost new.

Quote:

Originally Posted by Brian Carlton

It gets all the air it can possibly use unless there is a severe intake restriction.

Heavy black smoke is unburnt fuel. What's the IP timing and the camshaft timing...........did you verify?

I haven't verified timing yet. I'll begin to tackle that one tonight. My pickup sensor is sized for the 61x engines. These injector lines are smaller. Maybe I can shim it with something.

mplafleur · #**126** 03-23-2009, 09:02 PM

I'm 180 degrees out on the IP.

Arrrgggg!!!

I'll take it out tomorrow night and re-time it. Not seeing the tool click into place before, I must have thought it got locked in when it rose on the lobe on the opposite side.

Rick Miley · #**127** 03-24-2009, 01:09 PM

That part about running through 2 gallons of fuel was really puzzling. But then this morning it hit me - where was the fuel return line going? Back to the fuel source or to the tank? Maybe all that fuel is in the tank.

That sucks about the IP. But at least you found it.

mplafleur · #**128** 03-25-2009, 07:13 AM

I started to disassemble things so that I can retime the IP, but first I installed an EGR blocking plate I had made at work.

mplafleur · #**129** 03-25-2009, 07:57 AM

Quote:

Originally Posted by Rick Miley

That part about running through 2 gallons of fuel was really puzzling. But then this morning it hit me - where was the fuel return line going? Back to the fuel source or to the tank? Maybe all that fuel is in the tank.

That sucks about the IP. But at least you found it.

Yes, it went back into the tank. I didn't think about it at first either. I didn't know that much flowed back. This is not a high pressure gas system.

Ian White · #**130** 03-25-2009, 12:11 PM

Quote:

Originally Posted by mplafleur

I started to disassemble things so that I can retime the IP, but first I installed an EGR blocking plate I had made at work.

you must have acess to a CNC.

unkl300d · #**131** 03-25-2009, 06:51 PM

aside: great looking car! I hope the interior is excellent. (forget if it was mentioned earlier in your thread.)

Brian Carlton · #**132** 03-25-2009, 09:26 PM

Quote:

Originally Posted by mplafleur

I started to disassemble things so that I can retime the IP, but first I installed an EGR blocking plate I had made at work.

Need some SS button head cap screws............

mplafleur · #**133** 03-25-2009, 09:29 PM

Thanks, The interior is much better now that I replaced all the seats. I have newer door panels to go in too, but the yard that took them out broke most of the plastic hanger/clips on the inside.

mplafleur · #**134** 03-28-2009, 12:38 AM

It runs again!

I took out the IP, re-timed it and put it back in.

It started up fine with a little cranking and settled down to a nice idle. I checked the timing with my electronic injection timing tool and it showed 12.5 degrees at 630 rpm. The electronic idle control is set to 630, so it seems to be working just fine. I drove around the block a few times and noticed a few things:

1) the oil pressure gauge is not pegged, but wavers between 2 and 3 bar. I can get another sender from the pick-n-pull. I will also get a mechanical gauge and put it on to verify good pressure.

2) The temperature stabilized at about 90 degrees. This is too high for my liking and would prefer it to be around 80.

3) I was burning noticeable oil at first. It may have cleared up. It may be this way until the rings seat? Maybe the valve seals need replacing.

4) The valve train is a bit noisy. I hope the squishy cam followers pump up or I may need to buy 11 more.

5) There was oil burning on the exhaust manifold and some trans fluid down by the bottom of the tranny fluid dipstick tube. I didn't put the stick all the way into the tube so I hope it came from there. We will see.

6) It puts out a good cloud of grey-black smoke when I stomp on it.

mplafleur · #**135** 03-29-2009, 03:24 PM

Not only does the replacement sensor also show I have a possible problem, it may be worse than I thought.

When cold, I get up to 3 bar. As the engine warms, it's lucky I get up to 2 bar. When hot, I'm lucky to get up to 1 bar.

I did not plastigage the bearing clearances when I installed the crank and connecting rods as the crank had just come from the machine shop.

What about the oil pump. I've not had one go bad before, but here's what I'm thinking now:

The original oil pressure sensor was bad. It was basically an open circuit which shows up on the gauge as full scale. If the previous owner had a failing oil pump and didn't know it because of the bad sensor, it may have been why the engine threw the last connecting rod and started to weld the bearing shells to the crank. The crank was not in good shape which was why it needed reconditioning.

I am still working on putting in a mechanical gauge to confirm this. I just need to get a 1/8"-27 to M12-1.5 adapter.

Are oil pumps rebuildable or do I have to get a new one? It may take a couple of months for me to get enough scratch to buy one.