More than dead fuel ...
 

Got the old gas out with a siphon, and ran the fuel pump to get the last gallon or so. Also did a volume test (plenty of fuel), and replaced the short piece of fuel line (leaking) where the supply line meets the fuel rail. That required removing the power steering pump, which was fun.

Put in some fresh gas, and ran the pump for a minute or so to get the air out and tried to start. Not good. Clouds of blue smoke, running very rough, but less stink. Pulled the plugs out - they were sooty and dry, not fouled. Verifed that the plug wires were correct with a continuity check.

At this point, the troubles don't seem to be fuel or ignition-related. The one time I have seen something like this was a 380 that had a intake valve not opening, pulling oil up past the rings. So next step is to have a look at the valve gear.

Other ideas?

Valves look likely to be the culprit, especially after what the PO said. Milage seems too low to need a valve job, though...

Good luck! There aren't enough early 107's cruising out here in NoVA!

nice looking find. I like the red on red. I agree with the valve suspect. If not spark or fuel must be compression.

Truth is stranger than fiction
 

I am telling this in more detail than normal.

Got home tonight planning to pull the valve covers, and if there were no flat intake lobes, to keep going on the heads. But I thought I would check a couple of things first. #3 plug wire had weird resistance readings last night, so I clipped the timing light on it and cranked it. The light flashed, so the wire was good. But the odd thing was that the car almost started. Before it took a long crank to get it going. So that led me to think about fuel pressure and maybe it was lower because the car had sat overnight.

So I hooked up my gauge to the cold start valve feed, jumpered the relay and observed 7 bars of pressure. The spec is 2 bars. So I adjusted the regulator screw to bring it down, put the relay back in, and started the car. Stuttered a bit, settled down at idle, and proceeded to warm up like, well, a perfectly normal car. No smoke, blue, black, gray, or otherwise. Good oil pressure.

I am not making this up.

I backed it down and drove it up the driveway a couple of times, tidied up the garage, and called it a night.

sounds like you have it solved. it may just have been that crud from the old fuel was holding the diaphragm closed and you had too much pressure and just moving the screw may have loosened it up for the diaphragm to start moving again. I didn't even think the regulator would adjust high enough to hold 7 bars!
cheers
Barri

You may be right, but it wasn't like I touched the screw and the pressure dropped. It came down gradually as I turned it maybe 1/4 turn.

The spec with the return line pinched off is about 4.5 bar (64 psi), so the fuel pump may be going out. But it's not making any noise.

It's all very strange. There is an obviously new Mercedes-labelled fuel pump and filter, and all new hoses back at the tank, like someone made an effort to get the car going once before.

sounds about right. the djet pump should put out a little over 70psi. I used a cis pump (runs up to about 120 - 130psi) in place of my djet pump and had to put a regulator next to the pump set to 70psi with the return from the regulator plumbed into the return at the tank to get the pressure down to where the djet regulator at the engine could cope with it. As I remember the regulator at the engine would run between about 10 and 70psi although mine took a lot more turning when I was checking it.

Chuck can you detail this for me, I would like to do this on mine
What kind of gauge?, Jumpered what? Adjusted where?

Ditto here. Knowledge I would love to have.

Don't you just love these kind of surprises?

I will do that, took the pictures last night. But I think I will start another thread so it will be easier to find.

Last night I gave the car a short road test. It's down on power, and is missing on at least one cylinder under even the lightest load. The tires have flat spots, no surprise, and thump like crazy.

So I checked the CO, which was at about 5.5%, and knocked it down to about 1%. Spec is .5-2%. Timing and dwell are OK, and vacuum at idle is 17".

The car does have a brand new distributor cap, rotor, and wire (Mercedes no less), so I think the next step is a new set of plugs. On the theory that running with the super-high fuel pressure may have trashed at least some of them.

thanks, that would be great, do you have a CO meter? I am trying to locate one to measure my CO, No luck locally

Yet another toy I wish I had...

Is one of those available in the tool rental program? Or possible from a place like Autozone? Once I get my fuel system back together, the CO was on my to do list...

Also:
Have you gotten around to cleaning the points yet? I would look into updating to a Pertronix unit as well. My M116 loved it and it took all the mystery out diagnosing that stupid/expensive control box & the ballast resistors.

I do have one. Its a "Gastester," made in the UK. I paid about $100 on e-bay. It works OK down to about 1.0 - 1.5%, below that it gets flakey and sometimes will go negative.

The way it works, is that you let it run in air for about 7 minutes, and calibrate it to 2.0%, which apparently is the CO content in air. Then you put the probe in the tailpipe and do your adjustment or take your reading or whatever. So, say you end up at 2.5%. Then you pull the probe out, and let it run in air for another 7 minutes, and you probably observe a different air reading. Say it's 1.8%. That means you have to subtract .2 (2.0 minus 1.8) from your final reading. You would add the difference from 2.0 if your end calibration was higher. So your real reading would be 2.3%.

So it's most accurate in it's early readings, and you never know exactly where you're at if you've been tweaking for a few minutes. So what I will do is re-calibrate to 2.0% and take a quick final reading to be sure.

Hope that's not TMI.

New plugs, different tires
 

Yesterday I put a new set of plugs in, and changed the tires/rims. The ones that were on the car thumped so badly that I don't think I could really tell the tire vibration from the engine missing.

Also put 5 gallons of gas and a can of BG44 in the tank. And flushed the brake fluid.

Then I drove the car five miles or so. Without the tire vibration, nice ride, smooth, no clunks. The engine is better, but still doesn't feel right under load. It just doesn't have that smooth power you would expect from a 225 HP V8. I can't tell if it's a lazy injector(s) or a general lack of enrichment, or maybe this is what low compression does.

So for now the plan is to drive the car some more and see if the BG-44 helps, and maybe try some Sea Foam and a valve adjustment.

Now that she's running well enough to drive, I'd look at some of the smaller djet gremlins under the hood.

Have you replaced the vac hose that runs from the back left of the intake manny to the MAP? If the MAP isn't operating up to spec (either from that hose leaking or an internal problem) they can be sluggish. I have test procedures around here somewhere if you need them... I believe the MAP is adjustable as well...

Not as likely, but possible for how long it sat, is the 'full load' contact on the TPS. It might be worth pulling the cover and looking to see if the contacts look dirty.

Where did you set timing? Setting mine to spec made it run well, but setting it 'all in' made it run great.

I wouldn't rule out gummed up injectors either. That's one thing I love about these old girls: The more you drive 'em the happier they are. :D But if driving the snot out of it doesn't work an injector flow test might be in order.

I can't wait to get back to working on mine...