Engine running on two cylinders only?

I recently installed a new rotor; distributor cap and spark plug wires to fix an intermittent misfire in the vehicle listed above b2600i. I recently got but after the job the truck will only run on cylinder one and two. It's getting spark at 3 and 4 and it has remanufactured injectors so I have really no idea why it would be doing this. it also wasn't doing this before the new distributor just every once and a while it would drop a cylinder for a few seconds before it would come back. I also tried putting all of the old parts back in to make sure I didn't get something faulty; the only part I am mildly unsure of is if I got the rotor on right, but it went on in the same position as the old one. I also installed a new fuel pump fuel regulator and filter a few months back as the truck used to be a work vehicle at my job.