I apologize if I have missed this in a previous post.

I have a '91 560SEL 130k miles. Serviced frequently

While accelerating onto a freeway, hit about 80mph, the engine suddenly quit.

Towed home. Shade tree mechanic (myself) have discovered the following.

Plug spark confirmed (check #1 and #5 cylinders). Gas to fuel distributor and to cylinders is ok and pressurized and confirmed blows gas out of cylinder with spark plug pulled. Rotor turns with distributor cap removed, and seems to be aligned properly with appropriate plug at TDC - having only checked cylinders #1/5 at TDC). Can hear compression at each pulled plug as well (although have not checked compression with gauge.)
Fuel pump activates with key on.

So - have spark, gas and apparent compression. What next?

No clatter from a potential timing chain break. Doubt timing issue as compression blow is consistent at 2 of the cylinders.

Here is my ignorance with this injection engine. I sprayed starter fluid into the air intake and get no "fire"...not even an attempt to start or kick over.

Could this be an issue with fuel frequency timing valve? Or fuel distributor govenor?

thanks for any help and advice