(finally fixed) Crank, crank, Craaaaank, won't start thread...

I have seen quite a few people having similar issues, so I thought I would share mine so far and how it's going with me trying to fix it.
Quite a few of the threads about the crank crank crank won't start issue have been different problems and with a lot of the people it seems they have not resolved the problem.

Maybe we should consolidate and put everything right here?

https://youtu.be/dwf0c34RlxY

This video is my issue and how it's going so far, I apologize in advance. I'm not a videographer and I don't have a great camera or phone or whatever.

 

Summbich... Crapped out again, won't start...

 

I would have the ECU tested
Yea t get another to test

 

At this point, I'm probably going to have to limp her to Toyota and deal with the dealership bs. This issue has me totally stumped

 

Just found a potential clue!!
If i dis connect the battery for a few minutes BEFORE attempting to start, it will start!
Just did it about 5 times and it fired right up each time.
Then attempted to start without disconnecting battery first and it would just crank but not start.

 

Is the red security light flashing in the middle of the dash near the clock with the key on?

 

Check for power to the 10A EFI No2 fuse with ignition ON.
That will help narrow down the path a bit faster.

 

If the computer detects a rich condition it shuts off the injectors to save the motor. Might be a good clue to investigate.

 

Thank you

 

Thanks, any idea why it would be rich , even after the intake is clean? Fully open injectors??

 

I've never seen that red light. Maybe i don't have it, maybe the light burned out before i got the truck?

 

It looks like this on my truck.

 

I definitely don't have that. I'll take a picture of my dash tomorrow

 

No problem. Just now getting time to watch your video.
Let me watch it, and I’ll see if I have anything to add.

 

As far as I know all 4.0L trucks have an immobilizer and should have a security light, it blinks once every few secs with the key out but should go out when the key is inserted.

 

Ok. I watched the video,
a few things that might help.

1. The Fuel Pump Resistor is for low speed, idle, and low load.
When the pump is on high speed it by-passes the resistor.
The truck uses high speed to start, then quickly switches to low speed through the resistor.
If you unplug the resistor, you have to jump the connector to keep the truck running.

2. That thing that was stuck, is for the intake runners “I think”.
It changes air flow through the intake at certain rpm. I don’t think it is active until 3,500 or more?

3. For more explanation of my prior post on checking the 10A EFI No.2 fuse.
Why I say this is, the immobilizer cuts power to the EFI relay.
The EFI relay supplies power to the 10A EFI No.2 fuse.
The fuse is easier to check than pulling the relay.
If you have power to that fuse with the key ON, and it still isn’t running.
I’d move on to the power at the injectors.

Let us know what you get on that EFI fuse, we can go from there.

BTW, @Dm93 is excellent on this stuff.
Surely we can get somewhere on this?

 

Correct, you can also jump power to the Black/Red wire at the resistor to make the fuel pump run.

Correct it effectively changes the length of the intake runners at higher RPM's (not sure what RPM's it changes), wouldn't have anything to do with a no-start.

I'm not sure the method the immobilizer uses to disable the engine (many vehicles just disable the fuel injectors, some (not 2nd gen Tacoma's) disable the starter and fuel injectors), perhaps I need to experiment on mine and see but agreed it would't be a bad idea to check for power at that fuse.


I see it looks like you have or had an aftermarket security or remote start system (little indicator light drilled into the dash to the right of the switch blanks is a telltale sign of one being present), those can do some crazy stuff when they act up depending what all they are wired into.

I also see you have an aftermarket key, again I'm assuming your truck has an immobilizer do you have another key you can try?

You can try jumping power to the Black/Red wire at the fuel pump resistor when it doesn't start and seeing if it does.

If your scanner can read data see if you have RPM's when cranking.

OE engine wiring diagram below if you need it.

 

@Dm93
I missed the security light in the video. Good catch.

I don’t know exactly how the immobilizer works either.
It looks like the Transponder Key ECU has 2 Input/Outputs - EFIO and EFII.
Those go to the ECM, and are called IMO and IMI on the ECU.
As for what they do, and when they do it. Well that’s for someone like you to find out.
I am not confident enough to mess with that system. Lol

Might also note, that the Transponder ECU also has a connection to the Unlock Warning Switch.
My guess is, there need to be a physical key in the ignition as well to start the truck. (Grounded)

On the Immobilizer diagram, it only shows a connection to the EFI Relay.
I haven’t looked to see what all the EFI relay powers……yet

 

Thanks! I'll head over to get a new test light first thing in the morning

 

Hey guys, i just remembered that i was having a strange issue years ago.

Check this out
https://www.tacomaworld.com/threads/beep-beep-beep-while-braking.344864/

On the second page (i think) i put three videos in one post. Sorry, they are also shitty videos, but might be a clue.
Thanks again for sharing your electrical knowledge.