New transmission, now cranks but won't start

[Shakethatcas]

Hi, new to this forum but I find myself in need of some advice. I'm not very familiar with dodge vehicles, haven't worked on them as much as other brands and this truck has me stumped.

2001 Dodge ram 1500 with a 318 and a 46RE transmission.

The transmission went out in it about a year ago. The engine had run fine since then, starts fine every time. We'd crank it up and move it around as necessary. We bought a new crate transmission and hooked it all up and now it cranks but will not start. Poured gas in the intake and it runs as long as you keep the gas flowing there. Took the schrader valve out of the injector rail and pulled as much gas out until it ran clear because I thought maybe there was bad gas. Still no luck. Did some research online and checked the crank sensor and it's wires and they are not pinched or out of place, all the fuses are good, and all the connectors for the transmission are hooked up.

The only thing I've noticed different so far is that the oil pressure gauge doesn't move when the others do, and it was working before but I wouldn't associate this with a crank but not start unless it had to do with the pcm.

Any help would be greatly appreciated, been trying to fix this truck for too long.

 

[DodgeTx]

try starting it in neutral, if it start its a bad sensor telling it that its in park. However sounds more like a bad fuel pump to me? Other will chime in soon I'm sure.

 

[WilliamS]

If it cranks but no start its not the park sensor. Im betting something isnt plugged in. Crank position sensor perhaps.

 

[Shakethatcas]

The fuel pump is working because it pumped fresh gas I put in the tank up to the test port on the fuel injector rail. Pumped a couple gallons of bad gas out by doing that.

I tried starting it in every gear to see if it was possibly the safety neutral switch or maybe the shifter was misaligned but it did what it was supposed to with both of those options.

Had to stop messing with it due to bad weather but as soon as I can I plan on investigating more with the crank sensor.

Any other inputs would help greatly.

Sent from my SM-G965U using Tapatalk

 

[RamblerReb]

Did you check to see if you have spark?

 

[Hero6]

He has spark, as he stated that he can pour gas into the intake and it starts, so it really sounds like a pump. I know you said you can get gas to flow, but what is the fuel pressure? Pick up a cheap fuel pressure tester and see what kind of pressure you are getting at the fuel rail.

 

[Yeret]

I'd check the crank sensor. It fits into the bell housing and you would have had to pull it in order to swap the tranny. Make sure it's in place and wired up.

The computer itself acts as the switch for the fuel pump when the engine is running (there is a separate circuit that "primes" the fuel pump, that's why you hear it run for a couple seconds when you turn the ignition on) and it keeps the circuit closed as long as it receives a signal from the crank sensor. If it does not receive input from the crank sensor, the computer will not close the circuit and the fuel pump will not run. Crank the engine all you want, but it won't run if this is the case.

 

[RamblerReb]

He has spark, as he stated that he can pour gas into the intake and it starts, so it really sounds like a pump. I know you said you can get gas to flow, but what is the fuel pressure? Pick up a cheap fuel pressure tester and see what kind of pressure you are getting at the fuel rail.

Oops, missed that somehow in my original reading. Fuel, then.

 

[dragracefan]

Odds are is that when the transmission was installed the crank sensor got bumped and it fractured inside. If memory serves me right certain things wont turn on while in cranking mode but will work while in run mode. if the ecm does not see a crank signal it wont turn on the fuel pump while cranking but when the key goes to run position it will run. Also you stated the oil pressure sensor is not reading, this could have be hit while installing the transmission causing it to not work.

On the other hand you might want to look at the harness behind the distributor and double check for crushing or pinched or cut wires, because both the crank sensor wires and oil pressure sensor wires hang out back there and can be easily crushed when installing the transmission.

The cam sensor in the distributor will run the engine but not sync properly with the crank sensor. adding fuel to the engine during cranking is just supplying the fuel that isn't being provided during the cranking operation.

I'am curious why this thing hasn't thrown a code.