Enigne hard to start

It is firing, else woudnt back fire thru intake I believe. How do you check the fuel pressure regulator on one of those?

Took spark plugs out. They soaked in fuel. Cranked engine over with plugs out to clear out the cylinders. Put in new plugs. Cranked engine, again it tries to start, but wont. Checked plugs again, again soaked in fuel. Thinking fuel pressure regulator or crank sensor? Not able to check the fuel pressure. I believe it has spark as it is trying to start. Kinda stumped at moment. Any advice or suggestions?

Put new plugs in. Car cranked & ran like a new car. Drove it around for an hour, parked it at home, went to start it & same thing. Turns over, wont run. Pulled plugs out, they soaked in fuel. Again, changed plugs. Car ran fine. No miss, no hesitation, nothing. Runs perfect. Shut the car off, once it cools off it wont start & floods it. Dealers mechanic is telling son nothing wrong with the car & he just starting it wrong, which I know is BS. Did do a spark test, when car is warm it has a great white/blue spark. When cold, has a weak orange spark & you can smell fuel under the hood. Im sure the pressure regulator needs changed, but what about the cold start weak spark?

Ok, Tested fuel pressure. 98psi to the regulator. Put in new regulator. Replaced both coil pack with new ones. Replaced ignition wires, & spark plugs. Had ignition module tested, they cycled it 25 times, each time it passed. Put it all together & tried to start the car, acted like it wanted to fire & run, backfired through the intake a couple time & again, cylinders are flooded with fuel. Also now there is oil/fuel in the air breather.
What should we try next?

I don't think it's the timing belt. Reason I say this is for the following. When you put new plugs in it, it will crank & run. The first few seconds it struggles, chugs, sputters & bucks, but if you hold gas pedal to the floor, it finally picks up & runs & idles perfect. No miss, no hesitation plenty of power. Will go all day like that. But you shut it off & it sits a few hours, you go to crank it & under hood smells strongly of fuel & wont crank, pull plugs out & they literately are dripping of gasoline. To get it to start again, we have to pull the plugs, using a propane torch, warm them up till gas evaporates, pull the fuel pump relay, crank engine with plugs out to clear it of excess fuel ( and a bunch sprays out) let it sit & air out for about 20 minutes, put plugs back in & start the process over again till it runs. I did test light the injectors. They kept the light lit for aprox. 2 to 3 seconds & shut off. We cant test the MAP sensor, as you have to take the throttle body for the air intake off to get to it. We also change the oil & filter, was very diluted with gasoline. I was pondering the thought that maybe it is the ignition module even though it tested good. Will do another spark test tomorrow. But also wondering why after changing the fuel pressure regulator, it's still flooding out? Any chance it could also be a crank or cam sensor? Im stumped.