10A INJ Fuse

Yes, incredible community and so far the best responses I have received are from this community. I am very thankful for everyone who takes the time to post here.

 

SO the next wire to verify is from connector EA1 #14 to connector IH1#5, then from IH1#5 to connector E14#7

Since they have replaced the injectors harness, but still missing the "other" side...that would be the harness to verify after...
IH1 is inside the cab near the Engine Control Module.
E14 is connected to the Engine Control Module.
Engine Control Module is behind the Glovebox...

 

While I continue to diagnose the wires, I will show you a diagram of what I have replaced so far. The entire engine harness (the green) has been replaced. The direct injector harnesses (teal and blue) 82126 and 82127D have been replaced. I am currently waiting for shipment of the port injector harnesses (red) 82125N x2. I will be installing those as soon as they come in. Meantime, I am waiting for the fuse to pop again. I will be running the truck tonight. Once it pops again, I will start testing the connectors behind the glove box. Thanks again all for all your inputs. Hoping to get this fixed!

 

Well since you've replaced the entire engine harness (GREEN), that includes the IH1 & E14. It be great if it were the remaining RED harness

 

Say if the red harness does not fix the issue, would that indicate the Engine Control Module being the issue? I find it strange how intermitted the run time is between fuse pops.

 

My guesstimate would be no. The input to the Engine Control Module is a "signal". The injectors are the main items that draw the most current (or an elusive ground)

 

Interesting and good to know. I know my upper injectors tested around 12.4 OHMS each. I am seriously hoping the red harness fixes the issues. Should be in Friday or Monday.

 

So far changed out that last harness. Had the truck running for about 30-45 minutes and no fuse pop. I’ll be putting together the rest of the interior tomorrow and try and daily the truck again and see what happens. Fingers crossed.

 

Yup so went to drive the truck today, put the key in, turned it right before you start to crank the engine and the fuse popped... any further suggestions anybody?

 

What else is pushing power to the INJ fuse from the EA1 plug when the key is switched to ignition?

 

As far as I can tell, from the overall schematic... the injectors and the ECU... that's it.

If its blowing fuses that frequently, I think you should be able to find the bad wire or device with an ohmmeter... (just my guess)

 

I'd be running an ohm meter on sections of the harness (all should be near zero-10ohms), and re-test your injectors to be sure resistance numbers, and write them all down. ANYTHING that is fed from the INJ harness, as well as check for continuity to ground from the INJ circuit. testing injector to ground resistance, as well as open circuit from the injectors, another option is to unplug injectors one by one.. it will throw a misfire code, but will help you narrow down if it is a single injector.

my bet is on a bad injector... does this happen more-so on high humidity days? makes me think of the bad coilpacks on VW's where they ran find during the warm dry days, but in high humidity/ainy days they ran like crap, or not at all.. the coil casings were cracked. and would misfire the ignition to ground.. an injector is similar in this respect.. it is a small coil.. just not sure how it is drawing enough amperage to blow the fuse.. just a thought.

 

I guess I’ll put my money on a faulty injector. Every harness that feeds from the fuse box to the injectors to the ECU is brand new and replaced since the issue started. The injectors all tested 12.4 when they were originally pulled though.

 

this is why I chose a bad injector. the ohms may test well, but if a case is cracked, and possibly grounding out "occasionally" if you have access to an injector tester, or even a oscilliloscope, it would be good to find out if you have one that takes more amperage to fire.

 

just to be clear here, I'm not saying continue to throw part at it, rather spend the time doing proper diagnostics.. I prefer the "south main auto" youtuber approach.. diagnose, and use appropriate tools to test, duplicate, and prove faults, and then replace faulty parts.

 

I agree, I’d much rather diagnose, but when the mechanic flew in he was following Toyota‘a direction and they said to replace the engine harness and injector harness. Wanted to follow their direction to a T to try and submit a warranty claim later. Now the mechanic is no longer here so the truck is parked.

I’ll take a further look at the upper injectors.

 

for SAG I watched this vid... https://www.youtube.com/watch?v=k0yG3TwXBEw goes to show it may not be something obvious.... till you move the windshield wipers...

 

So the injectors are fine and not the problem. I am still at a complete lost.

For whatever reason, when we take apart the intake manifold, turn it over to get at the injectors and harness and put it all back together, the truck will run for a unspecific amount of time ranging from 15 minutes to 45ish. We may have done that on a occasion of four to five times and every time everything is put back together that is when we can get it running briefly.

Any other suggestions folks? What on earth could be popping this one fuse intermittently?

 

Update***

I unplugged everything that is coming off engine harness that I could get to with the intake manifold off. After that, I put a fresh 10A fuse in with the key in ignition and it did not pop. One by one I plugged in each connector and provided power from the key. Well, when I get to the driver side ignition coil, closet to the cab, the fuse pops as soon as I plug that connector in. I was able to replicate the fuse pop every time. I attached a photo of the ignition coil.

I have so far ordered a new ignition coil and should get it in two weeks hopefully. I will provide an update on here if this works, but so far it is looking promising. Finger crossed as this vehicle has not been drivable since April/May.