Integra 1991 LS with 95 LS stock engine.

[rexsomnii]

Hey guys, I need some help. Yesterday I was driving my 91 LS with a 95 LS engine in, . First I tried to accelerate and there was barely any response but i can hear the engine trying to go.. it felt as if it was about to die.

Also if im driving for long period of time, then if i go above 60+ km/h i get the engine check light.

One more thing.. If im driving and my temperature gauge goes cold.. what does that mean?


Any ideas of what could be wrong?
THANKS!!!!

[TypeRNammer]

thermostat needs to be replaced?

[rexsomnii]

When i drive normally, it stays in the middle but when i drive with the heat on, the temperature goes cold

[6o4allmotor]

Replace the t-stat like stated before.