Oil pressure problem

[K-Jet]

K-Jet
While rebuilding the engine I replaced my lower oil pan with the newest version. I replaced the oil pump as well and to find a proper clearance I measured the pump protrusion out of the upper oil pan, than check the depth of the new lower pan. I add few millimeters to allow for proper flow. Why did I go through all this trouble? Well, there are several different pickups. They all look very similar but their reach, angle and height are slightly different. I used the latest pump version (from M130) with the older pickup assembly. No rubber extension.
I’m not posting the measurements here as different parts combinations will very the final height/clearance. This step needs to be performed by you.

I can conceptualize how to calculate the clearance between the pickup and the pan. Is there a specification for that? Do you have a recommendation?

The oil pump clearly bumped up against the bottom of the sub pan. I would get anew one if it's available.

New, deeper pan means also new rubber surround as well, right? Is there a part number handy for that?

I intend to go to work with some wood blocks, a hammer and a large clamp and see what I can do. I can have an answer on this pan before it's possible to order another.

[Pinder]

I think that's a good idea to beat it back to shape and see if it makes a difference in pressure.

[MarkCan]

I replaced my oil pan because it was damaged. Maybe not as bad as yours but still significantly enough to cause flow issues. My other concern was the mating surface to the upper pan. Someone before me attempted to fix that by adding another gasket. Needless to say he failed miserably. As for the pump, I replaced it because it had a hairline crack, probably happened at the same time as the pan damage.
 I would remove the pump, inspect it and if all is good put it all back together with the new oil pan and gasket. Nothing to worry about. As Joe mentioned earlier it will take little more oil to achieve correct level with the new (deeper) pan in place. No need to worry about rubber attachment at the bottom of the strainer as your reference point (dipstick) position has not changed in relation to the oil pickup.
https://www.autohausaz.com/pn/1230100028
At $44 bucks you can’t go wrong. Although I would definitely get a better quality gasket. V.R. are hit and miss.

[K-Jet]

Maximum oil pump dangle: 64.6 mm
Minimum lower oil pan depth before adjustment: 61.4 mm
Minimum lower oil pan depth after adjustment: 72.1mm

Result: Nearly ionstant 3+ bar pressure at startup, maintained in driving. Problem solved! Thank you all so much for your help, experience, advice, and company. 

Next:

- Awaiting new replacement pan to install at next oil change

- The new engine runs poorly. As a next step, I need a shop that will clean injectors and MFI pump. I haven't found anyone local, and my MercedesSource tester filled my nearly new injectors with crap. Suggestions or recommendations? The pump was rebuilt recently but sat two years on a shelf not well protected enough.

[Kevkeller]

Have you tried pulling spark plug wires one at a time to see if you can isolate the roughness to one or more cylinder?

If it is you might have a stuck piston in the FIP which you can fix. There’s other posts regarding that fix.

[K-Jet]

Wire brushing spark plugs made a huge difference. The idle is still a bit lumpy, but we're definitely running on all cylinders. I may go back and pull the plug wires one by one just to be sure....

Now to research the belt squealing problem.

[rwmastel]

Maximum oil pump dangle: 64.6 mm
Minimum lower oil pan depth before adjustment: 61.4 mm
Minimum lower oil pan depth after adjustment: 72.1mm

The "adjustment" is hammering out the pan?

I need a shop that will clean injectors and MFI pump. I haven't found anyone local, and my MercedesSource tester filled my nearly new injectors with crap. Suggestions or recommendations? The pump was rebuilt recently but sat two years on a shelf not well protected enough.

How did the injector tester introduce foreign material (crap) into the injectors?
Why do you think there's a problem with the MFI pump?  Did you see something or test something?
I'm just saying, don't make assumptions.

[K-Jet]

The adjustment is hammering out the pan between wood blocks.

I'm not sure if it's rust or decaying seals (probably rust, as the test pump still makes pressure), but several of my injectors tested beautifully for a second or two before clogging. Backflushing afterward yielded black grainy goop of various particle sizes.

The injectors were bought at the same time the 2.8 pump was rebuilt and calibrated. The new injectors were subsequently installed to clear up its running problems on the 2.5 motor that was installed in the car. However, the 2.8 injection pump sat in an open cardboard box on a shelf for two years.

Given the sensitivity of the entire MFI system to contamination, it was unwise to let the pump sit that way, and it may help clear my sputtering idle and poor cold running. These problems were greatly helped by cleaning the spark plugs, so I will probably leave the injectors and pump alone for the time being. But better to look for help before you need it, right?

[rwmastel]

Oh, so the rust in the injectors came from running them in the 2.5 motor.  I thought you meant it came from using the MercedesSource tester kit (with which you would only use known clean fuel).  Bottom line, if the injectors have been back flushed (I'd like to understand how that process works!) and are now clean, and that pump that set on the shelf a while is now on the M130 and working fine, then I'd just use it as-is, keep the fuel system as clean as possible, and see if problems arise.  You mention cleaning the pump.  I'm not sure what preventative maintenance you can do now, but if there is some, then members here will chime in.

[K-Jet]

No. They ran fine for two years in the 2.5 motor. In investigating them as a problem source in the 2.8 motor, they started out with the nice whistle then clogged after a second or so of opening.

Backflushing is fairly simple. Pull open the business end of the injector with a soft thin metal tool or thin string, then use a syringe and tube to force cleaning fluid backwards through the injector. There's nothing ultrasonic or high-tech in the approach. I don't know how the effectiveness compares to what professionals do.