engine performance reduced when hot - Toyota Nation Forum : Toyota Car and Truck Forums

camry300 · 10-09-2005, 03:45 PM

My 93 v6 performance is very good when the engine is cold but the performance decreases a bit when it is fully warm up. Waht could be the causes????

would it be the O2 sensor ( no cel light ) because O2 sensor only comes into the picture when the engine is fuuly warmed up?????? or other causes?

Please help

terrastrife · 10-09-2005, 07:30 PM

how much is "a bit"?

all engines loose some power as hotter air is less dense so less air = less fuel = less power.

camry300 · 10-09-2005, 07:50 PM

well it is only by feel that the thottle response both partial or full thottle will be less pep when the engine is fully warmed up. ??????

Mike Gerber · 10-10-2005, 02:46 PM

Check the ECT (engine coolant temp sensor). It may be a slight bit out of spec (not enough to throw a code) and causing an overly rich condition when warm. It may think the engine is still a bit cold. You can check it with a DVM. The specs should be in the skinny at the top of this forum.

Mike

***ModifierMR*** · 10-10-2005, 03:00 PM

my car is the same way. The ECU tends to add more fuel to get the engine hotter for the Air/Fuel sensor to work properly. So you may get better performance when cold but it will suck on gas milige.

I have a problem where my ECU thinks my engine is alsways cold and so i waste alot of gas.