I have noticed an oddity with suction, but not that there is no suction. The checklist says to check for 3.75-4.25 on the gauge.. Mine always shows 4.75 though. Is weird though that you have it working on one machine and not the other..
Doubt it is the FSX.cfg file though, as that just controls your permissions. Only thing I think that may help there is deleting the Accu-Sim permissions out, and re-authorizing them when you restart FSX? Sometimes re-authorizing the DLL's fixes the weird issues I have.
It's the same machine & the disks are identical from a week ago when I cloned them except for the buttons & switches setup with Configurator/FSUIPC & SPAD (Saitek). When I setup Starter & Primer to a Toggle switch on my CH Quadrant, Suction STOPPED & that was on the Disk that was working.
Could be the keys I assigned - I will change them today on the Disk with a problem, but first I will follow your suggestion of deleting the Accu-Sim Permissions.
Key assignments can do strange things, at one stage if I turned on the Battery with my Saitek Switch panel the Gear handle came up & the Gear COLLAPSED!
I am getting very good at STARTING this Fantastic machine.
Here is why I LOVE the Mustang
Australian built CA-22 (Recon P-51D - Camera on the left side). Coffs Harbour Australia.
That's ME in 1949 hanging on to the wing tip (I WANT TO TAKE IT HOME!)
After that Flying was IT for me & I got 33 years of wonderful times in the air from Bi-Planes to Airbuses.