What is wrong with my 1988 pontiac fiero formula?

[lilkhmerraider]

So, i figured my car was overheating and that my engine coolant reservoir (green liquid in it) needed to be filled to full. The radiator has been topped off and the color liquid is green. Auto zone guys say i need to use GM specified Prestone 50/50 coolant. This is orange in color. I fill up the reservoir to full and the car started fine. I drive it a block away to my house and as soon as im done parking, the car stalls out again. It hasnt started since. What could be the problem? Mixing different colors? Thank you.

 

[pedro7of9]

not coolant problem
90 % of the time its ignision
9 persent fuel related
1% other

 

[Zimgxp]

If you mixed the green and orange coolant, you need to drain it and refill with one or the other. Some newer coolants will mix with dexcool, but dexcool does not mix with the older green stuff.