420A Hanging Rpms?

[Joey Burger]

97 Eclipse 420a Auto. after getting my motor back in i noticed my rpms are hanging and it idles like crap. Noticed my temp gauge wasnt working so i checked my wires and noticed that where the little slip over wire under the big temp sensor was broke off. so i took it our and soldered it back together just as a test, (already had to replace it) now it reads all the way hot the second the car starts. but i still have hanging rpms, i may just be stupid and missed something but im tired of guess and check, anyone got an idea?

 

[dsmcrzy]

First off what did you replace when you put the engine back in? I'm guessing you rebuilt or put a used engine in? Need more detail as to what new parts you have.

That smaller temp sensor may be bad if it's old. The small one is what runs the dash dummy gauge. The bigger 2 lead sensor is what the ecu uses and actually provides useful data. If it's old it's worth a shot just replacing it. Those aren't expensive at all.

Idling poorly could be old spark plug wires, old spark plugs even the timing being off a touch.

Hanging rpms, check for vacuum leaks. That's the most common cause besides a dirty throttle body.

 

[Joey Burger]

i replaced the head gasket, i triple checked my timing and its not missing at all, ran perfect before hand now it dosent.. My temp sensor got bent a little bit on the frame but it bent right back ony was a small little tweak.. could it really have done that much?