Service engine light on

Yes to the heater core.

No to the fuel pump. That could be the throttle body or the idle air control valve on the throttle body.

https://www.2carpros.com/articles/throttle-actuator-service

Roy

I have 1997 Neon was running good. sat 6 hours at work, cranks up, backs up then forward 3 foot and shut off. thought was fuel changed pump, same thing.Changed crank sensor, cam sensor, map sensor an coil pack. was cranking over but no start. I am not getting fire out of the coil pack. had pulse fire on middle wire but not sure about other 2. Checked timing believe it good.i got pressure on fuel rail..I'm lost and need some help on which way to go.

You need to check the actual fuel pressure with a gauge. You can rent a tester at a parts store.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Start there.

Roy

I just had good friend put the car on code reader an the code was P 1390. cam/crank timing. is that saying timing belt needs be replaced?

Yes. I would check it out to be sure. When there is too much slack in the belt it will set the code

Roy

thank you. and when I get tore down I just need make sure the marks are in line before pulling belt??

Okay, just pull the cover and see if the marks are aligned.

I attached a view below for you to view.

Roy