Changed distributor on a 2002 gmc safari and cant get it to start

This just happened to my Dad's 1998 GMC Safari...

Firstly...

Check the hard vacuum line as previously noted by others.
If that's ok, then take off the intake pipe and spray brake clean into the throttle body while trying to crank it.

If it starts.. then you have a fuel related issue, if it doesn't start then you have an electrical related issue.

Our van did not start after trying to use brake clean.

Take off the console inside the vehicle's cab and get at the distributor.

Usually people noted that the ICM (ignition control module, inside the distributor) was the main issue here, but on our van, the distributor and wires looked brand new so it was probably recently changed (we got this van 5 months ago), so I assumed the spark plugs were also changed at the same time.

We unplugged the connection from the coil to the distributor, tried to crank it, and no spark was being generated, boom, got a new coil and starts up fine.

Just takes a bit of trial and error.

check to make sure no codes also try new mass air flow sensor

ignition coil most likely as you have changed all the other/recommend replace ignition coil

2002 Safari 4.3L engine, cam sensor, same as pick-up coil, sits in ignition distributor, will be the one with three wire connector, held on with two small bolt's in the distributor.

my van starts for 2 seconds and dies.i changed fuel pump,filter,distributor,module,cam and crank sensors and still does samething

go trew the dog house or center cover in the vechile

Roll the engine around until the compression stroke on number one cylinder (both valves are closed) and stop on top dead centre. The rotor should be pointing to the number one terminal on the distributor. If it is not extract the distributor and replace it with the rotor pointing to number one. That should be it. Hopefully their are no other issues relating to the original breakage so you should make sure the new distributor is spinning normally.

replace the fuel pressure regulator and the fuel filter, the pressure is low.

Try changing the fuel filter and checking the fuel pressure at the shredder valve. The readings should be 60 to 65psi with the fuel line pressurized with the engine not running, once the engine is running. It should drop by 5psi. Start with the simple things first. Keep me posted, be glad to help.

DEPENDING ON WHAT TYPE OF DISTRIBUTOR CAP YOU HAVE?