My son in law bought a used tundra 2007, 5.7 liter, Automatic, 17,000 mile early last year it now has 24,000 miles in July of that year is when he had the 1st issue and continue onto this day happening more as weeks go by. The truck will start at time and other times you can just grind on the starter after ten times or so it will try to fire let it set and try it again it fires and runs. When it starts it has never died on him at a stop or under way. It seems that when it is warm is when it gives him the more trouble (unpredictable) The check engine light has never came on once. He has never taken it to Toyota but a very reliable mechanic he has used code readers with no help to solve the issue. Hope you have all the information to help us out. Would like to be the best father in law on earth. Rickey
Code readers won’t generally help with a starting issue because they don’t store fault codes during the starting protocol.
Here’s an easy and free check to try. It’s a crap-shoot, but with limited symptomology and intermittency of the problem, it’s worth a shot. When the symptom occurs, have him try turning the key to ON a few times for three or four seconds each before turning it to START. If that solves the problem, it’s a sign that the fuel pressure in the line has been lost. That would point to a failing check valve in the fuel pump assembly.
Post the results.
If you’re saying that the hard starting only occurs when the engine is hot, the problem might be vapor lock.
Vapor lock occurs when the engine heat boils the fuel in the fuel rails. This then makes it very difficult to get the engine started.
Have your son-in-law carry a bottle of water in the vehicle.
The next time the engine doesn’t start, open the hood and pour the bottle of water over the fuel rails
If the engine starts after doing this, that’s vapor lock.
Tester
And if it’s vapor lock on a modern fuel-injected car, it points to a weak fuel pump or a failed check valve, see @the_same_mountainbike 's comments. One check would be to connect a fuel pressure gauge and see if it’s in spec.
First thank you for the reply, The fuel pump pressure has been check and is OK, I forgot to mention that we have removed the air inlet in front of the throttle body and with my son in law cranking the starter and me spraying gas in the throttle body the engine will run as long as I keep spraying gas, when I stop it stalls we and after letting it sit and cranking it will start in time. I have heard that this is a no no spraying fuel in the throttle body. Hope for a follow up from you. Rickey
You have to check the residual fuel pressure.
Connect the pressure gauge.
Turn the ignition switch on without starting the engine, and then turn the ignition switch off.
Now watch how long it takes for the residual fuel pressure to bleed down to 0 PSI.
Depending on the vehicle, it should take 15-30 minutes for the residual fuel pressure to bleed off.
If it bleeds off rapidly, it’ll cause vapor lock when the engine is hot.
Tester
First thank you for the reply, The fuel pump pressure has been check and is OK, I forgot to mention that we have removed the air inlet in front of the throttle body and with my son in law cranking the starter and me spraying gas in the throttle body the engine will run as long as I keep spraying gas, when I stop it stalls we and after letting it sit and cranking it will start in time. I have heard that this is a no no spraying fuel in the throttle body. Hope for a follow up from you. Rickey