96 chevy lumina 3.1 NEED HELP

I own and automotive shop and have never come accross a problem with a vehicle like this. the customers car is a 96 chevy lumina sedan with the 3100 motor and has around 105,000 miles. car died on her when she was driving it so she had it towed to my shop. i put it on the scanner to read the check engine light and it cam up with several codes all leading to the cam position sensor. cam sensor was bad, wires were rubbing together. i have replaced the cam sensor and it cleared the check engine light but still wont start. plugs and wires were replaced 2 weeks ago, and i also checked for spark and it is good on all 6 cylinders. so from there i checked the fuel pressure and injectors, both good. the only thing i can think of is the crank sensor, but from the engine diagram shows there is 2, one on the back side of the motor and the other behind the balancer. i hat to replace one and it be the other and i hate not knowing becuase it is not throwing the check engine light and giving me a code. if anyone has come accross this issue please help me out. customer is on a budget and i would like to keep them happy.

Make sure the wiring for the crank sensor behind the balancer isn't loose and rubbing the pulley, or the other one can be popped out of its keeper and laying on the exhaust on the back side.

Just for laughs, did you try hitting it with starting fluid? Just to see what (if any) reaction?

Make sure all of the plugs going into the module under the coil packs are secure. They are actually not that hard to knock loose, if one jams their arm around the back trying to work with plugs and wires. They'll slide right off the module if you're up against the clips tight enough.

yes i hit it with starting fluid. still no fire. it acts like it wants to but doesnt. i inspected the wiring by the crank thinking the same thing but it is good. i did also check the coilpacks and they are all plugged up. it is getting spark and fuel but no fire almost like the timing is off wich leads me to the crank sensor. but i am hesatint about wich one to change since it is not throwing a check engine light.

Make sure the camshaft is not broken, common issue,

You have spark, you have fuel pressure. The engine cranks. It would be worthwhile to test the compression on each cylinder; and worthwhile to check injector pulsing with a noid lite.

First Guess: Fouled spark plugs. Having spark at the plug wire does not mean you have spark across the plug gap.

When you pull the plugs to test compression, you'll be able to inspect them for fouling.

What is the electrical resistance of the injectors? Are you sure fuel is going to the cylinders?