Truck starts and idles only

Well I seem to have a problem responding. This is the third attempt. The truck is running after pulling the oil pump and spindle held the rotor at 12 o'clock and installed the pump again. Started right up but misfire at lower rpm. Number four cylinder plug is fouling. Don't understand this it's new plugs. What's your opinion? Thanks JC also replaced MAP and MAF sensor. Still has a miss.

Okay Alex, thanks for the information. By the way it's a 1997 truck. Anyway, the plug is not soaked in gas but it's the only plug that has lot of black smut. It wipes right off. But the smell of gas is present. I don't mean like a gas leak. But exhaust gas. Thanks JC

Alex, another update. Started right up idles very smooth very little tapping didn't let oil pressure build up. Because I noticed there is too much engine movement. New mounts on engine. But seems to be side to side movement more than should be. Correct me if I'm wrong but I think the oil pump and spindle are the problem. Before the rotor was pointing past the number one wire on the cap. Now it seems to be pointing a little before the number one wire. I may be splitting hairs but I think given all the new parts on this engine it's in the timing. I hear no unusual noise from any particular cylinder but the engine should run smoothly and not jump around. What should I do now. I know my marks on the cam gear and crank gear as well as the chain links we're all aligned. I triple checked these. What to do now. I hate to take the timing chain cover back off. It starts so good I don't understand what's going on. Thanks JC

Will the engine run at 180 degrees out?

Alex, part of my problem was the picture showing the position of the rotor is wrong. I pulled the oil pump three times before I figured this out. Regardless of what the picture shows the rotor must point directly to the number one on the cap. Truck runs good has lots of power after 2,500 rpm. But holding the throttle steady on around 2,500 rpm the rpm will drop all the way back to around 1,500. The misfire seems to occur when slowly acceleration or holding steady on the throttle between 1,500 and 2,500. No tapping or ticking is present. Engine sounds good, but after a complete rebuild I should not have this misfire. I'm stumped and ideas or suggestions please feel free. Thank you, JC

No oil on plug it seem to be dry just has a black smut deposit on it. The other three do not have this problem. I bought the plugs in January 2019. Maybe I need hotter plug and some new wires. The distributor and rotor are new. The whole distributor is new actually. What range plug do you recommend? I'm running NGK plugs. Thanks JC

Thanks for the guide, but I'm afraid it's a little more serious than just a plug. Yesterday I worked on timing. I'm not sure what it is but but I've got the timing advanced as far as it will go and it runs pretty good, but I know this is not normal. My crank pulley marks line up on mark when the number one is at TDC. Have you ever encountered a situation like this before? Thanks, JC

Wow, now that's a new one on me. But very creative that will be fun seeing the out come. Alex, I got a question but first I want to say I'm thinking this misfire issue is vacuum related. I've switched vacuum hoses around and made no difference. But while doing this I hit a wire harness plugin I'm not sure what it does but it effects the way the engine runs it's one wire coming out of the bottom of the intake below the throttle body. And it comes up and plugs into a grey male plug? I've got to work on getting you some photos tomorrow. Anyway here's my question:
I'm not a great mechanic by no means I'm almost 70 years. Old and still climbing under vehicles and doing repairs. Done this all my life because I couldn't afford to pay a mechanic. But back to matter at hand I pulled my oil pan today after a month of driving since the rebuild and while checking my rod caps torque specs I noticed something disturbing. There is a minute bit of sideways movement in the the rods and cap on each cylinder. I say sideways I mean lying on my back looking up at the engine movement is front to rear. Is this normal? Thanks JC
also Alex, here is the numbers on the plugs they sold me for a 2.4L Nissan engine: ZFR5E. NGK
11. R. JAPAN

I will let you know. I'm going to remove the head again and timing chain cover as well just so I know for sure the chain and mating marks all aligned properly. It's a lot of work I know but then there will be no doubts. I'm going to inspect the number 4 cylinder very well is there anything particular I should look for? Could I see if anything was bent? I will let you know what I find. Thanks. JC