1993 4.9 300 inline six
Idles great around 900-1000 RPM) but bucks and lacks power when taking off.
new: MAP sensor / O2 sensor / IAC sensor/ TPS / Distributor / Fuel Pump / IAT sensor / ECM and Engine coolant temp sensor

Any idea/help would be GREATLY appreciated

 

Measure fuel pressure, at the rail, on both tanks if you have two.

 

Try pulling the vacuum line off the EGR valve and plug the line with a golf tee. Go for a spin and see if the bucking stops. If so, check for a lean miss which would indicate a vacuum leak or a problem delivering fuel out of the injectors(dirty injectors, low fuel pressure, blocked fuel filter).I had same thing with my 87 and the injectors were dirty. Remember, test don't go shot gunning new parts at it.

 

I can't seem to find a schrader valve anywhere to test it

 

It's a shame that on the straight six, it's so difficult to remove the injectors or the fuel rail. I've been stealing parts from my 1991 inline six to see if anything changes. No luck yet
As a note...changing computers (from my '91 to the '93) made no difference either. I also replaced the three capacitors that commonly fail.

Still at a loss. Frustrating part is, I'm a good backyard mechanic. Grr

 

It's hidden between the firewall & the intake cage.