Crank but won't Start in the Morning.

My Taco doesn't want to start in the mornings, it can CRANK but doesn't start. However, in the afternoon when the environment is warmer, it starts without problems.

I have already changed the fuel pump, sparks and also the fuel pump relay.

I live in Puerto Rico which is a humid island in the mornings.

HELP!!!

 

Any codes?

Does the CEL come on with the key on when it won't start?

Does the security light next to the clock flash with the key on when it won't start?

Does the tach move when you crank on it?

Have you pulled a coil and checked for spark while cranking?

 

^ what he said


will it fire up in the morning with a little bit of starter fluid?

if it fires up and runs for a few seconds on starter fluid, that will tell you there is spark but no fuel...

also, check your air filter for mold. i am not sure why, but a moldy air filter below 70deg F will choke the engine, but if its hot, will run fine. (I also live in a wet sauna)

separate topic, but with the moist air, you need to check your oil fill cap for Frappuccino. if you only make short trips, the moistness never evaporates from the engine oil.

 

With the key ON and NOT cranking, The check engine light should be on.
With the truck RUNNING, it should not be on.

Check to see if the CEL is ON with just the key on when it happens next time.

 

How old is the battery?

 

good morning,

no check engine light is ON POSITION in the morning!

 

I believe your 2010 has a cold start valve it's purpose is to squirt a small shot of fuel into the intake while cranking it's kind of needed for a cold start regardless of the temperature.

 

So no Check Engine Light Key On-Engine Off is a good clue, that means the PCM is offline so the truck isn't gonna run.
Now it's a matter of checking powers and grounds to the PCM when the problem is happening but first lets check the EFI and EFI No 2 fuses for power with a test light with the key on. That will give us some direction.

No cold start valve on any 2nd gen, those were from the early days of fuel injection. Haven't seen one of those since the 90s.

 

Then either the EFI Relay is bad.
The control for the relay is missing.
Or you have a ground issue to the relay (not likely)\

I'm betting the control signal is missing.

But try swapping the Horn relay with the EFI relay.
See if the truck starts. That's probably not the problem. But it would be nice if it were that simple.

 

hello, this morning I swap the relay but still without power the fuse

 

Today I noticed when these happen, I put the key in on position and I heard two click in the motor fuse box area!

 

Help

 

So when the truck is broken check at the EFI Relay terminals as shown and see what's missing

At the EFI relay, key on.
Pins 1 and 5 should have power and pins 2 and 3 should be ground.

Test light to battery negative and pin 1


Test light to battery positive and pin 2


Test light to battery positive and pin 3


Test light to battery negative and pin 5

 

Hello i tested these morning, 2 and 3 tested and both good. 1 is without power and 5 have power!

 

That means the ECM is not commanding the relay to turn on.
we need to check powers at the ECM.

 

For now, check your 15A IGN fuse.

Let me dig up diagram of the ECM.
It's not hard to check. But it may be "hard" to explain how to check it.
There's like 5 plugs at the ECM. You just have to make sure you are on the correct plug.

Let me work on it. I'll get back to you latter.

 

Check the IGN Fuse first.

Then go to the ECM behind the glove box.




KEY ON for these test.

At the ECM. You need to check POWER on plugs.
E11 - Pin 23 (Light Green)
E13 - Pin 24 (Blue)
E14 - Pin 21 (Beige)

Grounds on
E11 - Pin 12
E12 Pins - 10, 11, 14, 15, 16, 18