Hey all,
Im having a tough time trying to figure out what in the world is wrong with my co-workers 87 240 DL.

Symptom: will not idle, backfires through intake manifold, has to rev engine to keep running then surges all over the place while trying to keep it running.
Tested/looked at:
-Timing belt and marks - all line up and belt is in good shape
-New plugs and wires(last november)all are hooked up correctly
-new main fuel pump and in-tank works
-cleaned throttle body
-cleaned flame trap
-cleaned plugs/gapped
-compression 185psi on all 4 cylinders
-new fuel pressure regulator

At the end of working on it, the owner decides to squirt some carb cleaner into the throttle body where the charcoal canister lines go to and the thing smoothes right out for about 3 seconds then stalls as it always does if you arent revving the hell out of it, it was incredible. So after that we determined it HAS to be a fuel problem (am I wrong??). We tried to get a hold of a fuel pressure guage but cant get one. That was going to be my next step. Then test the spray pattern on all of the injectors??

We're going crazy here, anyone have any ideas?
Thanks a bunch,

Adrian