Friend of mine. Has 98 ram 318. Motor was bad s9 bought differnt one. Heard it run (ran just fine) in the other ram before he pulled it and brung it home. Yanked the one out of his. Droped the fresh one in. No fuel.....pump not come on. Pulled bed of. Put new pump in.....still not come on when turn key on
hes looked. And said no blown fuses.....is there a reset for the pump? I would thought swaping out the motor the bat would been undone so should of cleared any codes if that possible to come up
what about ground on it???? He said it dont come on for a sec or anything like its not hooked up/power to it

Take a close look at any wiring you were even near to do that eng swap. I was thinking about that crank sensor on rear of engine, but the pump should still get the 2 second power when key gets turned on IIRC.

There is an ASD relay.It should click and prime the pump for roughly 3 seconds.Id say check power and ground to pump.Sounds like a ground is missing or the relay isnt coming on.Every time the key is turned on the pump should run as I said for appx 3 seconds.Rocky

I agree with Rocky,also how did he check the fuses? Pulling them out and looking at them is NOT the correct way to check fuses. A voltmeter or test light on both sides of the fuse with the key on is. Make sure you check ALL of them..underhood,underdash,etc.

Yeah. I k ow what it should be doing...lol thats just it. Its not doing it...my thought 2as a ground. But not sure exactly how that system is grounded
That may not be the problem either....his truck ran but motor was junk. So up to pulling the motor it would still start n run......swaped motors. Now fuel pump no workie

You said the truck is a 98, what year is the engine out of?

Were all of the electrical connections made?

If the engine is from a different year, did you use the sensors from the original truck engine?
That can possibly make a difference.

I believe that the fuel pump gets it's ground through the computer (JTEC, NGC).
If the computer is not getting a signal from a sensor it may not be sending the ground to turn the pump on.

A buddy found that out the hard way when he converted his truck from fuel injection to a carb.
Without all the sensors hooked up the fuel pump wouldn't get a ground and the pump wouldn't run.
He ran a separate ground and then the pump worked.

The new motor is also a 98 318
he t9ld me just now. They (his father n llaw) even sprayed either in the aircleaner trying to get it to fire
I told him he needs to keep him away from the truck

The obvious questions, but have to be asked to help diagnose it from here.

How did they verify that there was no fuel being pumped to the fuel injector rails?

There's a schrader valve (like a tire fill valve) on one rail. It has a black cap on it.
If you press the center of the valve and there's no fuel coming out it's definitely a pump type of issue.

Has "ignition spark" been verified.

Ive seen the pickup wires pinched between the trans and motor a lot when engine or trannys are swapped.Rocky

The bed is still off. The old pump (wich worked fine before the swap) stoped working so took b3d off. Replaced the pump. And hit the key to just to make sure before put bed back on. ...it also will not cycle for a sec when first turn key on. I told him it needed grounded. But wasnt sure if it grounded through the harness or had a strap. Or how it was set up

check for 12v at the connector at the lower part of the left front of the cab, it should be the green & black wires, check the pins in the connectors as well or hook 12v directly to the pump connector on the top of the tank

The connector has the ground and hot in it.The pump will run even outside the tank if its connected.You need to check the pump relay and the ASD relay.It should click when key is turned on.Then get a test light and check for power and ground at the pump.Run a long wire from the battery so you know you have good connections.Rocky

One thing is when you check for voltage on the power wires make sure you backprobe them. In other words leave all the wires connected when doing voltage checks. Thats the only right way to check for proper volts to and at the pump because if you have resistance in the circuit it can still read 12 volts when open circuit checked. Ron

the asd relay has to fire up first,then fuel pump relay energizes, Does the engine light come on with the key cycled to the on position?if not, computer not turning things on, you have a broken wire, missing ground, bad connection somewhere. Get a test light and start checking things. fuel pump relay ( as most relays) needs 2 power leads, 1 hot all time, 1 with key on only, computer controls ground circuit, the other lead goes to the pump.The pump will only run for a second or 2 with the key first turned on. Do not expect it to be running all the time the key is on. once engine runs, the relay reenergizes and stays running. Is check engine light on?

One of my Dad's friends had a 97 Dakota with the same problem. Turned out that the power wire was broken between the relay center under the hood and the pump. Soldered in a new piece of wire at both ends ($5) and it was fine afterwords.

Get the ohm meter out and make sure you have continuty between the relay plug and the plug at the fuel pump. I bet you don't. They are standard type relays.