Here's the deal -
87 non-turbo RX7
Cranks just fine - starter is NOT the issue.

Car won't start when it's cold, but seems all right when I re-start after it is already warm.

I can roll it down a hill and drop it into 1st, and it picks up just fine and drive normally after that.

Any thoughts?

 

Water thermo sensor on the back of the water pump housing is disconnected OR if you remove the plug and look inside the elect plug, you might find one of the two terminals is pushed back and not making contact when the elect plug is attached to the sensor.

The sensor is a key player in starting the car. IF disconnected the ECU will default its value to 176*F.........therefore HOT starting will be ok, but cold starting will be punk.

 

Good thought. I'll check that when the car has cooled off.

It's the green one on the top end of the pump, right?

Thanks!

 

yes

 

Couldn't easily pull it off - tried to push it on a bit better and that seems to have worked for now. I'll look into it more later.

Think that's the issue. Thanks a ton, Hailers!

 

It has a wire retaining clip you have to release.

 

How is the compression?

 

An engine with low compression usually starts just fine when cold but is difficult to start when hot.

The water thermo sensor on the back of the water pump is a major player in how much fuel gets delivered during STARTING the engine. The ECU looks at the water temperature.......the rpms being under 500rpm and the START signal being seen by the ECU when the key is HELD to START.

 

I think it may have just been needing to be wiggled back on. If it acts up again, I'll pull it and clean the contacts.

Thanks!


Awesome. Thanks so much for your insight! I take it in my situation, while the car was assuming it was warm, it was probably not delivering near enough fuel to start, correct?

 

***Awesome. Thanks so much for your insight! I take it in my situation, while the car was assuming it was warm, it was probably not delivering near enough fuel to start, correct? ************************************************** **********************

Exactly right.