Car won't start when warm

[peachtits]

Just recently i started having a problem with starting the supra. When the engine is cold and hasnt been on for a while and i go to start it, it will start right up. When i start it, the car will run perfect, but then after its warm and i shut it off and wait like 5 or so minutes, the car wont start. The engine will just keep cranking and wont fire. If i leave the car there for a while and let the engine cool down again, it will start.

Mods: 3 inch turbo back exhaust, BOV, FMIC, wastegate shimmed to 9lbs

 

[jetjock]

Either you're losing rest pressure or the FPU system isn't working. Probably a loss of rest pressure.

 

[robbo185]

could be heat soak as well

 

[MDCmotorsports]

Stock fuel system will do this.

As Jetlock said, the fuel pressure up VSV isn't working propperly.

 

[peachtits]

I have a walbro 255 fuel pump ready to go in, will that fix the problem?

 

[MDCmotorsports]

It might help.... but I doubt it.

 

[peachtits]

So how do i go about fixing this problem?

 

[Nick M]

could be heat soak as well

That doesn't exactly narrow it down, but it is true. Old age plus heat equals high resistance, that is correct.

So the FPU vaccum switching valve might not be working when hot. And the fuel system is vapor locking. I have also seen ingnitors quit working when hot.

You can check to see that the VSV is switching vaccum to the pressure regulator.