2013 Tacoma cranks won't start

Hey Everyone,
This is the first time I've posted but have gotten a ton of help from ya'll and I really appreciate it! I have a 2013 Taco that was flooded in Hurricane Sally; I made the mistake of trying to rebuild it and have had one problem after another. A former Toyota technician rebuilt most of it for me and it runs well when it will run. I'll try to keep this short; had problems with crank and no start, replaced the fuel pump and it ran well for a couple of months. Then started having the "runs for a few seconds and dies" problem. This was sporadic, would run great for a few days, then have to crank it 10-12 times before it would start and run normally for the next few days. Then it decided to run once in a while. Took it back to the shop that replaced the fuel pump; they checked the pump and installed a new pump and neither would work consistantly in the truck, both worked if wired directly to a 12 volt source. They decided it was in the wiring harness somewhere. I found a harness on a 2010 that was in good condition and installed it. Also replaced the fuel pump resistor (new). Now it will crank but no fire at all. Any thoughts, any previous experience with a similar problem, anything would be appreciated at this point. What little hair I had is gone and not sure what to pull out next!! Thanks in advance!

 

Possibly the Anti-theft system.
The transponder key/amplifier/ or module.

This will let the truck crank, but it will not allow it to start.

 

Thanks TnShooter, I saw that someone else suggested crank 3 times, then lock and unlock 3 times, then crank again; tried that but no luck. I've been wondering about the anti-theft too. I've had the battery disconnected, the module was replaced and the key reprogrammed by a locksmith back when it was being rebuilt. The module was off ebay, most other parts and harnesses were from Toyota. All dash and engine room harnesses were replaced with new Toyota parts.

 

Ok, I read your post again.
So let’s get this sorted out.

It did run if the pump was wired directly to 12v.
You replaced the wiring harness, and it still doesn’t work.
Does it run if the pump is wired to 12v? Did you try that again?

I guess we need a starting point.

Do you have any codes of you scan the truck?

 

Yea flood vehicles tend to become electrical nighmares unless every single electrical component is replaced which is typically cost prohibitive.

Were the junction boxes and fuse boxes all replaced?

 

I don't have a code reader. I had the gas tank out to install the wiring harness but didn't think to check the fuel pump myself. The junction boxes and fuse boxes were replaced with new ones. All the dash harnesses are new as well. Back when the pump was replaced by the shop, I had had to run a wire around the harness connectors in the interior to get power to the pump (pins were corroded). I spliced in a new piece of wire on the black/red and after that the pump ran normally until recently. I ended up cutting off two connectors and splicing all the wires together in those two bundles to install the rear harness. All the splices are tight, I''ve done a lot of wiring and tried very hard to make sure I wasn't creating another problem. The shop tech said it would run if he sprayed starter fluid in it so I don't think it is a spark problem. Since I've replaced the harness and nothing has changed, I'm wondering how much experience the technician has. They're open today, I'm going to call and see if I can talk to him again. Thanks for your help so far!

 

So, after reading more posts I've been doing some testing. I've been following the path in the fuel wiring diagram in a previous post. The 20amp EFI fuse is good. All relays are good and the fuel pump resistor is new. I've been trying to check for voltage on the black/red wire that comes from the engine wiring harness into the interior and am not getting a reading. When would I see 12 volts there, when ignition is on or not until it's cranking?

 

Fuel pump on 2nd gens only runs when the engine is cranking or running, it does not run at key on so you should have 12v on the wire with the engine cranking.

 

Thanks for that! So, getting less than a volt (0.09) at the black/red wire when cranking. Any ideas on why no voltage?

 

Check for voltage on the Black/Red wire at the fuel pump resistor, if there's none there you will need to go to the C/OPN Relay and Fuel Pump Relay to check things.

I'll have to pull diagrams when I get time to help you further.

 

Ok at the C/OPN Relay pins 2 and 5 should have power with the key on, the PCM grounds pin 1 to turn the relay on so if the powers are good you need to see if you have a ground at pin 1 of the relay engine cranking.

 

Sounds good, I'll be trying these in the morning. Thanks

 

Ok, I got 0.9 volts at the black/red at the fuel pump resistor, engine cranking. There was 12 volts at the 2 and 5 position on the C/OPN relay with ignition on, about 4 ohms resistance at pin 1 when cranking, 0 when ignition on. I connected the black lead of the meter to the battery ground, the red lead to pin 1 and set meter to 2k Ohms, then cranked the engine. Was that the correct way to check for ground?

 

Preferred method to check for ground (or voltage for that matter) is with a test light connected to battery positive to check for ground or battery negative to check for power but you can use a meter set to volts DC connected to battery positive as well, the light should light when it finds a ground and the meter should read battery voltage when it finds a ground.

Resistance is not a good test as all it will tell you is that the circuit is intact, it won't tell you wheather or not it will carry a load.
Same thing with using a meter on a circuit that isn't loaded (see the video below).
https://youtu.be/xazvmJ8_p5Q

 

Not sure if this was right, VM set to 20v, red lead connected to battery positive, black lead to Position 1. Reading 11.5v with ignition on, 10.5v when cranking. It's a little cool here this morning, battery was only reading 11.7v, yesterday was 12.3v. Put it on a trickle charge but only about an hour ago.

 

Interesting, are you sure your on the right relay?

 

Yeah, the one next to the 10 and 30 amp fuses like your schematic. That's the one that's marked on the fusebox cover as C/OPN. What are you thinking?

 

I'm just curious why there was voltage there with just the key on.

Do you have a test light?

 

Yep, just watched your video too. So, black lead on battery ground, other lead on position 1?

 

If your checking for a ground you want your light connected to battery positive, if your checking for power you want it connected to battery ground.