3.4 Cranks but won't start

I drove to school, and it ran fine, like normal, parked for about 4 hours and when I went to go start it, it just cranks but doesn't start, thought at first it was the fuel pump. I got it towed home and just today replaced the fuel pump but still doesn't start I checked the EFI relay and the fuses in the cab there all good. Got any suggestions?

 

I would assume you verified if you have fuel to the plugs or spark ? If no spark, could be crank position sensor?

 

Another possible problem. Could be your ECT (engine coolant temperature) sensor. On the 3.4L it is directly down behind the 3400 four valve on your timing belt cover. I mentioned your crank sensor. I think you can rule that out if, when you crank the engine, you will get a low rpm reading on your tach while cranking. If your getting that, then your crank sensor should be working.

 

I had a Mass Airflow Censer do the same thing on me when I had a Ranger.

 

do not throw parts at it.... pull a plug wire, stick a screwdriver or another spark plug and visually check for spark if there is or is not any spark get back to us.

 

It was throwing a code, it says camshaft position sensor so I am gonna check that next.

 

So happens that I have the same problem on my 2013 Tacoma V6, it started 2 weeks ago, I'm still searching for a real solution.
Meanwhile, I stumbled on a diagram and made a temporary jumper from battery to the center pin of fuel pump relay (sharpie red).
When the problem surfaces I jump it, start the motor and disconnect the jumper.
I am still waiting for the problem to be consistent enough to actually start looking for the actual cause.
I'll be tracking your progress.
Good luck
Tom

 

PROBLEM SOLVED!!
The bypass to the relay, mentioned above, was very temporary and eventually ineffective.
I followed the red line in the schematic attached. However, I found my problem to be not in the relays or breakers, or other aforementioned components, but at the cable harness connector that's on inside the cab right next to the parking brake. One of the connector pins lost contact, arced and burned out. So happens that this pin carried current to the fuel pump. . .At that, I ran a bypass from the wire section before the connector to a wire after the connector.