Stalling

Unusual issue, I usually don't post much on forums but this one really has me stumped. Please comment if you have seen anything like this or have any ideas. The truck is an 06' 4L double cab short bed auto trans. sr5 190k well used but well maintained.

First, the 2 things that were slightly different with the truck than my normal everyday use. I used one of my keys that I rarely use. Second I pulled a trailer about 15 miles home, (town driving) backed the trailer into the garage, then unhooked and closed it in (I was running late and didn't have time to unload it). I then got right on the highway. It was about 2 hours of highway driving both ways with a 3 hour stop in between and then I was back home, and parked the truck. An hour later I went out and started the truck, turned it around and hooked onto the trailer to pull it out of the garage and unload it. I pulled the trailer forward 15 feet and left the truck running to unload stuff in my garage. 2 minutes later my truck stalled. Didn't sputter or anything. Just died. I started it up and it ran for 30 seconds and died again. The next time I tried starting it, it was a crank no start. I didn't have time to deal with it and was frustrated so I went in for the night.

Then next morning I went out and added a few gallons of gas to the truck I figured maybe my fuel gauge was faulty, I never had any issues before but who knows...
Same thing as the night before but I did notice an engine light this time. Also I listened closely and could hear my fuel pump running. Anyway I started it, it ran for a while still nice and smooth. Warmed up some (temp guage went up 1/4 Of the way) and then it just died. Tried starting and it came back to life, started it again it died again. Once more tried to start it and it was now a crank no start. I took out the scanner and it has codes p0351 p0352 p0353 p0354 p0356 these are all ignition coil primary/secondary circuit codes. You might notice there is no code for cylinder 5... for some reason that one was left out. I cleared the codes and it made no difference, the light and codes came right back. I took out my test light and have good power and ground on each coil connector with a test light (tested when it was failing and a crank no start) I tried a battery reset, no improvement. It's Really weird I've had many vehicles throw one maybe two coil codes and run rough and misfire but this one does not run rough and doesn't seem to misfire but sets the same codes on almost all cylinders and just dies without warning. At this point I thought of the key and tried my usual key. I thought that had to be it, it all made sense now! Unfortunately I was wrong....same thing.

Has anyone seen anything like this on the 4.0 or does anyone have any other ideas? Any help is much appreciated!

 

Well with 5 apparently being ok, switch one of the coils to 5 to see if you pull a p0355 if you do then you know you got some dead coils. Weird. If it stays the same you may have a wiring problem in the ecu. I've seen this happen a few times in the obomination known as the 5.4 liter ford triton motor but not in a Toyota. Also make sure your spark tube seals aren't leaking oil into the spark tubes

 

Thank you for responding, I just tried swapping them, it made no difference. There is no oil in the spark plug tubes and the plugs We're done 10k ago. I have had this bad gut feeling it could be the ecu...

 

Maybe check out your CPS?

https://www.tacomaworld.com/threads/tacoma-died-randomly-while-driving.494847/page-2#post-15305525

 

Damn, the rpm looks good... I wish it were that simple

 

Check to make sure you have your 5 volt reference. Wiring diagram may be required. If you still need one in the morning I can pull one up when I get to work

 

Also pull the coils and check for resistance to make sure you don't have a shorted coil.

 

Thank you for the advise! I have been really busy and didn't get to look at it much during this week, Tonight i went out and checked power and ground again, they were good with a test light at all coil connectors key on engine off. I have 5v at every "IGF" pin on each coil connector key on engine off. I ohmed out the wiring between the ECU and all the coil connectors, every thing was good at .1-.2 ohms. I followed your advise Bebop and pulled all the coils and checked resistance between all the connector pins on every coil. #4 coil was a way different resistance reading than all the others and was an aftermarket replacement!!! The previous owner must have had it replaced, I have never put a coil in this truck. Anyway fortunately I had an OEM spare kicking around I pulled off a junk yard motor and the problem went away when swapped. The old coil must have been fine to run the engine cold but when it warmed up to a certain temp, it was a dead short and killed the whole ignition system before it could even misfire. I still have no explanation for it setting the ignition primary and secondary circuit codes on every cylinder but 5. I even tried unplugging 5 when it was running and it wouldn't set a #5 circuit code. Oh well, The truck is running great again, Thanks Bebop.

 

No problem dude. Believe it or not I've had bad aftermarket coils right out of the box. Toyotas are picky when it comes to electronic parts. I had a full tune up on a v6 Avalon before where pulling the intake is required to get to the rear plugs. I replace plugs and coils and get it out back together and the car runs like absolute crap with an immediate misfire code. It's a cylinder on the back bank misfiring. Luckily I was able to wiggle it out and switch it with one on the front bank and the miss moved. I marked the dead coil with a frowny face because I was off the next day so another tech knew which one to swap out.

 

That's a pain in the ass, atleast on these the coils arnt to hard to get at. I felt kind of dumb I didn't figure it out sooner. When I was a tech I never had one fail in that way before that I remember. It's unusual that it wouldn't misfire or show anything even for a split second on the misfire counter.

 

Misfire counters are weird also. I had a ford I had misfiring right in front of me and it showed zeros down the board.