Cranks but no start

Yes. If you have fuel, air and spark it will detonate.

 

Maybe something like a throttle position sensor or mass airflow sensor??? I saw on some car show somewhere that the car wouldn’t start and the tps was bad. I’d imagine that would be something you could test though???
However I did own a motorhome that did this same thing and it ended up being the computer. Went through a lot of parts and testing before we figured it out. I had a professional mechanic friend helping me and he kept saying “ it’s not the computer they never go bad”.

 

are you sure you checked all the fuses?

 

Update.



I visually verified that,

I checked all fuses that I am aware of. (A fuse list and schematic would help)
All injectors are spraying.
All coils are firing. (spark plug on the valve cover test) (Low tech)
The intake valves on all cylinders are moving.
put my hand over the TB and could feel the suction.
Replaced camshaft sensors and did not work.
Replaced crankshaft sensor did not work (OMFG! that was a job to get it changed)

The engine turns over and after 5 seconds it seems to try to catch but does not,

If it is the ECU, is there a way to know?



I am at wits end on this.

 

Does it run on starting fluid? Not brake cleaner/carb cleaner..

Do you still have the scan tool? Hook it up and see if the coolant temp is way out of spec. When they fail, oftentimes they'll read crazy negative, like neg 140 degs. It will think the truck is in Antarctica and it can flood the engine with too much fuel. Are the plugs wet with fuel after trying to start?

 

I will try the coolant temp Monday, I do smell fuel after the cranking.

I will get some starter spray and give it a try.

 

Maybe this will help.
https://www.tacomaworld.com/threads/2015-wiring.559639/#post-18289864

 

I mentioned this before but when the computer in my rv failed the only way I knew to test it was a little unconventional. I removed the rv computer and installed it in a “friends” vehicle that was basically the same platform and it behaved the exact same way. I did not want to risk damaging the good computer by moving it to my rv. New computer from GM and then had to have it flashed by the dealership. All I can say is I feel your pain!!!!

 

I had this EXACT same problem before and went through all the same troubleshooting steps that you have done, fuel, spark, injectors, battery, crank&cam sensors. Nothing made a difference it would crank and crank but no combustion. Ended up being MAF sensor had failed and was telling the ECM that it flowing like a ton of air and so the injectors were flooding the cylinders to the point that it wouldn't fire. Never through any CEL or stored codes or anything like that just crank no fire. Put a new MAF in and fired right up.

If you have a buddy with a 4.0 tacoma I would swap his MAF in real quick and just see what happens. Also would be worth checking voltage signal from the TPS as you gradually move the pedal from 0 to 100% to make sure its working correctly. Best of luck!

 

Hey OP do you have an update on this?