I have 86 FC rebuilt motor. Starts cold fine, runs great, but (after it warms up) if I turn it immediately off, then try to restart. It won't start. If I wait 30 -45 min it starts and runs fine again. I just replaced the injectors, fuel pressure is a little low 65 psi and I replaced the the water thermo sensor. Also ( after warm up) if I turn the car off, I can start it again, but I have to floor it while starting. Then it starts. Is this an water thermo switch issue?

 

well it isn't a Thermo 'switch' issue.
a thermoswitch is just what the name implies..gets hot/cools off and switches a circuit on or off.

A thermo 'sensor' is used to monitor temp and give the Ecu data it can use to alter fuel.(like the one at the back of the waterpump)
Now if it was disconnected or not connected or faulty then you get that hot start problem.

another guess would be that the injectors were not serviced properly or installation was not correctly done and you get a slight vac leak when starting as the engine is hot.

 

Where are you measuring for fuel pressure?

 

My car has had hot starts since I have owned it. I however don't have a rebuilt engine. I have changed injectors and still does it. Of course I already had a fix before I did all that. I also linked a thread below with the same issue. And another thread with instructions for fuel pump switch.

I put a switch inline with the fuel pump. I turn it off when it is warm to start the car then I turn the switch back on after it starts. Cheap and easy fix. I know this doesnt fix the actual problem, but it is way easier and cheaper and it works everytime. Put in a switch for $5 and be done with it. Anyways just my .02 Good Luck!

https://www.rx7club.com/2nd-generati...thread-932606/

https://www.rx7club.com/2nd-generati...switch-714741/

 

I measure the pressure straight from the line, dead headed.

 

smikels

Thx, I'll check it out, but this looks has if it for flooded engines...