1989 Mercedes 560SEL no start

[TylerH]

Hi, im new to the forum and am still learning how to use it, so apologies if anything seems off or is in the wrong spot, but my real reason for making this post is that I have an 89 mercedes 560sel that won't start. I bought the car roughly 2 months ago in perfect working order, I replaced my fuel filter about 2 weeks ago and its been downhill since. After the filter change It practically didn't start so I had it towed to a shop that "specializes" in these and they messed quite a few things up, they adjusted the fuel mixture screw completely out of wack and broke my EHA, they also had no diagnostics done for a week and no progress towards an answer. I decided to not work with them anymore and figured id fix it on my own. So as we sit, the airflow meter was taken out inspected, and cleaned, properly adjusted to 1.9mm of free play with no rubbing on the plate and smooth upward and downward motion, a new, leak free EHA was installed, a fuel pump relay, the injectors have been taken out and soaked in sea foam, along with an inline fuel pressure gauge installed on the supply line right before the distributor which reads 90 psi when pumps are jumped and 40-45psi when resting. I've tweaked the mixture screw 1/8 turn in both directions having the freeplay from practically 1.9mm to 2.5mm and the only start i had was at 1.9-2mm but it soon died. I'm quite lost in the process and would hate to buy unnecessary parts or tow it to another shop. Thanks for the help in advance.