Won't start when hot outside... [SOLVED!!!!!]

/Update July 2021 - I know this is an old post but nudging it in case others are experiencing since it happened to me again yesterday.

If your 2nd Gen Tacoma won't start when it is REALLY hot outside and the inside cabin temp is >90 degrees, check to see that the immobilizer light turns off when you insert the ignition key prior to cranking. (red blinking "car with a key" light). If not, open the windows, take the key out, (blow/fan the ignition hole, silly I know but works, or just wait 20 min). It is not the fuel pump, mass air flow sensor, coolant temp sensor, or any of the many other things people have replaced to track down this problem. Will try again to see if I can get the dealer to believe me.

-john

/End Update July 2021

~Begin Update~

Happened again today. Outside temp in the mid-90's. Truck wouldn't start. Finally noticed that the immobilizer light was still on and blinking while cranking. Pulled out key, noticed it was warm, blew into the ignition hole to "cool it down." Immobilizer light turned off when key inserted. Truck started right up. Didn't have to wait my normal 30 min (which I thought was for flooding to clear but instead was for ignition assembly to cool down since the windows were open each time this happened). Doh!

~End Update~


Its that time of year again in the mid-atlantic when your Tacoma cools down just enough for the engine to flood when you try to start it after sitting for a few hours. Wait 30 minutes and you're fine.

After days of searching, being amazed at the parts people have thrown at the problem, it appears some folks have had luck replacing the ECT (Engine Coolant Temperature) Sensor.

Anyone have any luck doing this on a 1GR-FE 2011 V6 Tacoma? Pointers on where this sensor is located on the 1GR-FE?

Edit: I found a diagram from the parts store but it looks buried


Thanks!

-john

 

First i have heard of a 2nd gen "Flooding"

Technically it cant do that on shutdown due to it being fuel injected.

 

I will try that next time it happens! Since it only happens when very hot out patience is short so not having to wait 30+ min would be fantastic! Thanks!

 

When you have the issue what happens? Just crank and crank but no fire?

also what year of truck?

 

Its a 2011 TRD V6 4WD approx 120,000 miles. Yep, just cranks and cranks. Tried cleaning the MAF sensor as well as leaving the MAF disconnected to go into "limp home mode" and still no luck. It is getting spark. The best diagnosis of the problem is that the computer thinks its cold so dumps too much fuel upon starting which then floods it. Wait 30 min and its fine. Has only happened on very hot days and maybe only a few times a so far. There are no OBDII codes thrown. A google search returns lots of folk with the same problem but not many solid fixes other than replacing the engine coolant temperature sensor so the ECU knows the engine is still warm.

 

Very interesting.

Also, i redact my above statement about holding the accelerator down and cranking, this is the first modern fuel injected vehicle that i have had that will allow one to hold the throttle wide open and crank and have it start up at WOT.


To simulate this, what i would do is keep a non chipped plain metal key, one that will not turn off the immobilizer when cranking. This will do the same thing. If you have the issue. Use the plain metal key, hold the gas pedal down to the floor and crank with that key (as the immobilizer does not allow any fuel / spark to happen), then put the regular chipped key in and go from there.

Also, have you tried turning the key to on to prime the fuel system, turn it off, turn it back on to prime again then start?

 

I'm hoping replacing the ECT sensor solves the problem and I don't have to try a work around... if I can find this darn part without taking the whole intake plenum off.

 

So, stuck again. 94 out and wont start. Was fine on the way in to work. Sat 8 hours and now just cranks. Holding throttle down (wot) doesnt do it either. Ugh...

 

I just noticed the immobilizer (red car with key) is blinking even when i turn the ignition on with the primary key? Could hot weather foul the immobilizer?

 

I'll write this up when I get home but this HAS TO BE A STICKY!!!

Hot passenger compartment causing immobilizer to not recognize the key!!!

[Edit]

Added update to original post instead of creating a new thread...

[Edit]

 

Wondering if a locksmith or legit key maker(not Walmart or Home Depot) is capable of cutting one of these from the chipped key w/o damaging it?

 

I got my chipped key cut into a standard metal key at the local hardware store without issue. Unlocks the doors and turns the ignition just fine.


And OP interesting, never had issues with an insanely hot cab causing issues with the immobilizer. Ill keep an eye out on the immobilizer light when i start my truck up after work to see its behavior.

 

http://www.customtacos.com/tech.old/files/05FSM/repair.html

Do a FIND for "coolant temperature sensor" - 1GR-FE engine should be 1st occurrence. You will be pointed to other sections of this doc as well in order to complete the task.

 

Awesome! Thank you! I didn't know these existed... Appreciate it!

 

So 3rd day truck starting by cleaning the mass airflow censor. I bought MAF sensor cleaner and sprayed the little wires until the black was gone about half a can and it’s still starting today and I’m running around. Make sure you let it dry completely before you put it back in.

 

No it can't do that on shutdown, but it darn sure can do that on start up if the engine coolant temp sensor defaults to -40 or whatever it's minimum parameter is due to it being defective.

 

Was it hot outside for the past three days? The next time this happens, before you mess with the MAF, put the key in the ignition, turn it to the ON position, and see if the "security/alarm/immobilizer" flashing light (looks like a picture of a car/truck near the radio) turns off. If it is still blinking the truck will not start until the ignition tumbler cools down. Typically takes about 10-15 minutes. (Same amount of time to open the hood, unscrew the two screws of the MAF sensor, and put everything back together. Yes, talking from personal experience.) If you want to speed up the cooling process, get close to the ignition key hole and blow in there a bit. Only happens to me when its 90+ and the truck is parked in the sun.

I went through a lot of troubleshooting and nearly started replacing several parts discussed in many threads before I noticed the immobilizer light wasn't turning off when it wouldn't start. Next time it happens to me I will make a video of it and post to youtube...

 

Excellent advice. I was having the same issue this summer when I left my key in the ignition for extended periods of time. I never checked if the immobilizer light was flashing, but there was a thread where someone with the exact same year and trim as mine had his immobilizer ecu replaced and said it solved the issue. From (I believe) a TSB bulletin, there is also the possibility of the ignition barrel acting up, but I believe this issue throws a code, which, when I checked, mine had not thrown. I have made it a habit to not leave my key in the ignition.
So far, so good. I have had the failure to start thing only happen twice, but that's 2 times too many. I was desperate, so ended up changing my fuel pump in haste. I would like to see this stickied, and find the two threads I was referencing in the same sticky.
Ok, here's a link to the ecu issue thread
I'll look for the ignition barrel thread.
Weird stuff. Happy I'm not alone.

 

Just bumping this post since it happened to me again yesterday. Its that time of year when the outside air is +90F and my Immobilizer needs to cool down due to the cabin temps. I'll get it fixed eventually. Leaving the windows open for 5 minutes was all it needed. Symptom is putting the key in the ignition, turning to the On position, and the Immobilizer light continues to flash. Please don't waste time on MAF sensors, Temp Sensors, etc. If its hot out and you crank without starting, confirm the Immobilzer light is off with the key in the ignition.

 

Get yourself a can of air, like "Dust Off". Turn the can upside down and give a very quick blast into the lock. That will cool it off real quick. Use caution though. Too much of a blast will freeze the lock. That probably won't be good for the surrounding plastics, lube, wiring, whatever. It will also condensate, and, you know, water wouldn't be good either.

Of course, I haven't tested this nor seen studies of this solution. It's "improper use of the product". It's a suggestion. Use your own discretion, bla bla bla.

Good luck Mr Phelps.