92 bravada problems

I have a 92 bravada 4.3 w vin. It runs fine in park and neutral. the problem is when its in drive
cant get to go above 20 mph and wants to stall out.
so far the cap,rotor, pickup, and coil,module, fuel filter,pcv have been changed fuel pump is only a month old. fuel pressure is 50 psi no leak down. manifold vacume has been checkek 18 in hg has good vac cat not plugged. after replacing the fuel filter and pcv valve halped some but still hard to accelerate with it. plugs and wires look to be fairly new about 6 months old. any one have any ideas what the problem could be? as im lost on this one

When you hit the throttle in park and neutral, does it hesitate, miss, or anything. How about when your in gear, does it miss, pop, or is it just a dead pedal? Any SES codes stored, light on? The fuel pressure is low, these systems are very picky, they need to be at a certain pressure range, or you will have problems. Is the 50 psi just key on, or is this at idle. Id be surprised if its at idle, as its too low, but I have seen stranger things happen.

When you hit the throttle in park and neutral, does it hesitate, miss, or anything. How about when your in gear, does it miss, pop, or is it just a dead pedal? Any SES codes stored, light on? The fuel pressure is low, these systems are very picky, they need to be at a certain pressure range, or you will have problems. Is the 50 psi just key on, or is this at idle. Id be surprised if its at idle, as its too low, but I have seen stranger things happen.
no hesitate or miss or any thing when in gear dead pedal 50 psi at idle. from looking at the specs ive seen fuel pressure should be between 41 to 47 psi. no codes either

Any chance the timing might be off? Did you have the distributor out?

The '92 CPI motor needs 52-56 psi fuel pressure. When you rev up the motor in Park, the fuel pressure gauge should show an additional 1 lb. increase.
Sounds like a rubber fuel line is pinched and the motor is barely getting enough fuel to even run...check your fuel plumbing.
Recheck your exhaust and listen for a "wisssss" sound while trying to accelerate...I had a crossover pipe on the stock single exhaust close up and you couldn't see it until I pulled the exhaust system down, '68 Impala 327/275hp...couldn't run faster than 40 mph WOT.

it just started doing this about a week ago was rainning out thats when the module cap and rotor where changed. checked all fuel lines they are ok. after putting the new fuel filter and pcv valve in ran ok part way around the block the started doing this again . it stalled out restarted fine the acted up again. starting to think its in the trans mission going to have it towed to the shop for a trans service. plus it needs a brake line now and I know thats not related to the other problem.