92 saturn sc hesitating and running rich

my 92 saturn sc dohc hesitates when i accelerate and it is running rich. ive already cleaned out the throttle body and map sensor and got a new 02 sensor but it hasnt helped yet. what do you think the reason its doing thins for?

Change your coolant temp sensor. The two wire sensor below the EGR valve. 13mm deep well socket is all you need. You'll spill a bit of coolant, depends on how fast you are getting the new one in.

Ok, lets try to keep the discussion here instead of PM's so that it might help future board users. You asked:

"How does the coolant temp sensor affect it like that. I wouldn't of guessed it would do anything."


The coolant temp sensor is absolutely critical to the PCM for proper engine management. If the PCM can't tell how hot or cool the engine is, it can't properly manage the fuel system. It is easily one of the most important sensors in the system.

When the car starts cold, the PCM adjusts the fuel mixture to a 'rich' state to keep the cold engine running smoothly. On older carburated engines this was the chokes job. As the engine warms up, the PCM can lean out the mixture because the warm engine needs less fuel to stay running properly. If the coolant temp sensor goes bad, the PCM will constantly run the engine rich just to be safe since it can't tell if the engine is hot or cold.

my 92 saturn SC2 dohc
:)

CF is totally on about the sensor. Supporting how important the sensor is the PCM also uses it for some of the following sub systems: Idle rpms, air/fuel, timing, emissions control, tranny operations (automatic), and fan control.

One more thing. Replace the ECTS with the 2-wire sensor. :)

Thanks for helping me out with this problem. I just put it in today and it ran perfectly. Their was no hesitation at all.

Cool. :smokin: