1995 Ford E350 XL cutaway (460 gas) Acceration Issues

Looking for help troubleshooting problems
No acceleration on hills actually truck will slow when throttle is pressed. If gas petal is feathered truck will maintain speed eventually will slow down
Recently bought truck has new fuel pump, filter, catalytic convertor and O2 sensor. seem like the last owner was chasing some issue?
Truck will run great 70 mi. then act up is key is turned off truck will run fine for 4-5 mi then die. Leave it set and it will run great again
thanks


RESPONSE

Your in luck as it is a 1995 Model. This means you can pull the Computer codes without a scan tool.

Post any codes found below in the comments for further help. If no codes are present than I would be looking at fuel pressure drop on acceleration. A drop in fuel pressure may be from the a leak or a failing fuel pressure regulator. At idle fuel pressure should be around 30 psi and should increase to 35-45 on acceleration.

If the problem seems to happen more when the engine is hot versus cold, I would lean more toward the ignition control module as it is the most common failure component in the ignition system for this year. And there will be no code for this.

1995 Ford E-350 engine component location diagram