I have a 97 dodge caravan 3.3 i have fuel pressure, cranks over swapped relays around new cam and crank sensor, new pcm, new coil pac, the van will sometimes spark once then only crank at the same time the injectors get one pulse then only cranks, i have also checked for a shorted injector and didnt find anything wrong, ignition switch works properly, not sure where else to go.

I don't know what testing you have done? Make sure battery has a full charge, Have helper crank it while you check for spark at the plugs. If spark everywhere use a gage and check proper fuel pressure and fuel injector pulse. If your missing everything, check cam and crank sensor signals. Some of these vehicles, the computer has to see both the cam and crank sensor signals or it won't ground the asd relay, that relay sends voltage to several system.
Any applicable trouble codes?

hi dean.
try this link it might help you find out why it will not start.
1997 dodge Avenger with 2 0 engine Cranks but no spark Google Search

no spark conditions could be faulty ASD RELAY OR FAULTY PCM.

I had one where the gauge cluster isnt working and van wouldnt start or would start and shut off after 5 seconds so make sure gauges are working

The inertia switch is in the rear of the car most times in the trunk area\


Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c

Okay, lets start with fuses, check all your fuses, then move on to scanning the computer for any stored codes, like pcm codes as chrysler has had computer problems, and make sure power wire from battery to fuse/ relay box is good and clean, then check your auto shut down relay maybe swap with a known good one, then last dis connect all injectors and check for a shorted one.

If you have good fuel pressure. Check for spark at any plug while cranking, If no spark, also place a screw driver on an injector and listen to it while someone cranks it over. If you have NO spark and NO injector click - crank sensor needs to be replaced. 95%
other 5% hmmm wiring problem on / near crank or cam sensors, theft system active, dead pcm.......

generally the spark would be from the crank sensor or the coil or ignition module or the computer could be bad. . Also if the ASD relay is bad you wont have spark and possibly no fuel pressure.

If you have replace new cam sensor with no sparks and the coil are good putting out 12 volt, my guess would be the computer it self faulty. cam sensor sense the cam turning and send info to computer telling computer to disperse the charge from the coil pack to the plugs assuming relay, cam sensor, coil, plugs, and wires are good. make sure the cam sensor is put in properly and position.

check the asd relay swap it with another like it. also check fuses and old car alarm if it had one.the cam and crank sensor will not affect fuel pressure. the cam sensor should not stop this car from starting. but the crank sensor will. good luck.