94 grand voyager 3.3 engine. Engine cranks but will not start. have changed fuel pump, fuel filter, relays, crank sensor. Still not getting power to fuel pump. I have switched out ECMs and coil pack. Have run out of ideas on what it could be.

i got a 94 and mine did the same thing. turns out it had a bad fuel pump relay and a bad asd relay. i switched the horn and asd relays with them and it worked like a charm. give it a try, it cost nothing. all those relays are the same

On Chrysler products the fuel pump relay only turns on when that ASD relay is energized by the computer and that happens during cranking, 3 to 5 seconds after you're done cranking or with the engine running. It is very common for the ASD relay to go bad and not allow the fuel pump relay to come on. Also, if the crank sensor has failed it will not allow the ASD relay to energize. These sensors and relays can be observed with a fairly inexpensive scan tool. If you go to a parts store to purchase one I recommend you ask 2 questions. 1) Will it read relays and sensors, live data stream? and 2) is the screen clear and easy to read with few abbreviations? I own 3 scan tools, 2 were under a hundred bucks, better one i think around $150.00 Cheap one is for lending to young kids with good eyes. LOL
I hope this helps

could be fuel issue, spark issue, electronic issue. i would try starting fluid in intake and see if engine fires at all. could be fuel filter, bad coil, crank sensor, engine computer. I would try running the codes on engine and see what codes are present and see if that gives any idea of issue.

check see if you getting spark if not.have vechicle code scan could have faulty ECM .faulty camshaft sensor and crankshaft sensor.make sure engine has been tuned up.replace fuel filter change spark plugs and wires. before engine can run need fuel and spark.either one not working car will not crank.

If the passkey system were not working the engine should not crank and the fuel injectors would be dead. The security light would also stay on.
The fuel pump relay gets battery voltage and also voltage from the key switch. The computer grounds the relay to power the pump.
The crank sensor does not come into play until the engine is cranking and it supplies a signal for the ignition and injector pulse.
Are you not getting power from the key switch to the relay, or from the battery side to the relay ?

Camshaft sensor very likely. Heat is causing it to fail. Could also be crank sensor. Cheap part to replace, very easy if camshaft (top of engine) check that first.

Back to basics. You need spark, fuel, and compression (manifold vacuum). Before you replace any more parts, check to make sure that you have no stored codes. If your check engine light is on, retrieving the codes will point you in the right direction. If you have to, tow it down to your local Autozone. They will scan it for free! If the check engine light in not on, the problem is most likely the fuel system. So, locate the fuel pump relay under the hood next to the driver side front fender. Remove it and CAREFULLY remove the top by lifting the two clip tabs with a small screwdriver. reinsert the relay and crank the engine while observing the relay to verify that the relay pulls min. That is, that the contact moves. If it doesn't, check the fuse and the relay itself. (Swap the AC clutch relay, they're the same). If it does, try manually closing the relay with the key on while someone listens at the open fuel opening, (take the gas cap off first) If you don't hear the fuel pump running, it is probably the pump. Please note that I own a 97 voyager that is very hard to start, and I have often had to manually operate the fuel pump relay in order to prime the engine so that it will start. Hope this helps!

you going to have to narrow it down to see what part is defective. first check make sure you getting sparks by pulling one of the cable and use spare plug and ground it making sure you getting fire when turning engine over. 4 things need to check for fuel delivery. fuse, relay, fuel pump and crank sensor. assumed fuse and relay are good, using 12v light tester locate the fuel pump connectors and connect pos and neg terminal and have someone turn engine over and see is you getting any power to the pump, if the pump is good, crank sensor will be faulty, what crank sensor does it sense the flywheel turning sending info to the ECU then the ECU send power to the fuel pump. keep in mind, fuel pump will only turn on as long the crank sensor sense the flywheel turning.

test replace the fuel pump relay, make sure the relay socket has 12 volts to 2 of it's terminal when the key is held in crank position, if not you may have a defective ignition switch or Powertrain control module (PCM)

What you need to do is drop the fuel tank and put a new fuel pump in it. I would drain the gas and put new gas in after you get the pump changed.