Starts cold when warm won't start until cold - 1991 Cadillac Allante

-It could be injector's relay. Fuel pump relay. (It works when still cold
but not work when it's hot or warm)

Mai

I am not sure what you mean? What will not even start up?-----------------------------------------------------------------------------------
2012 ELM327

it often happens in the winter, naturally, the cold weather will have some effect on all the car's system, especially the battery and cooling system.
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Easy to get a MST-3

First i would check the crank sensor by looking for rpm's on the tachometer or scan tool if you see any rpm's then crank sensor is good.Then check for leaking injectors and if they are not leaking then you will need to check the ECM it may have failed.

Had a similiar problem with mine. Ignition control module will overheat and the vehicle will not be able to restart until the vehicle and ignition module cool back down. Ignition control module probably bad.

sounds like either the starter solenoid is dying or a bad connection at the battery

The next time it won't start check the fuel pressure you should have 48-55 psi with key on and engine off.

Sounds like you might have a faulty ignition switch and ignition lock cylinder.These cars are known for the ignition switches getting hot and then they won't start.

Sounds like a leaky injector, bad idle ,hard to start when warm, bad gas mileage. Or the temp sensor both of them that won't let it run rjght when its cold

try the cold start sensor/ automatic choke