420A 2gNT 4000 rpm idle

[98dsm04]

So yesterday i went and picked up a 1999 eclipse gs auto just as a parts car but when in park it has a very high idle of 4000 rpm, but when i put it in drive the idle drops too about 2500 rpm. If you guys know any ways to fix this lmk. Thank you

 

[Sirius1995]

Most likely it has a CEL lit, you can do "keydance" and check codes if you don't have a reader, it will Morse codes for you with the CEL

It can be a lot of things but sounds like a intake/vacuum leak to me

 

[DSMPT]

The engine can not rev that high without the air. Most likely the throttle body butterfly plate/throttle cable is stuck open due to rust, improper adjustment, worn throttle cable etc. And/or a massive vacuum leak. Check if the throttle would be closed smoothly/properly and vacuum leak, especially between the intake manifold and the head.

 

[99dsmer4g63]

If the car does this cold or hot I agree with the above post and is most likely a vacuum leak. Either smoke test the car or go old school and sketchy like my dad a spray starting fluid around vacuum sources to find the leak. I suggest #1 but #2 will work to quickly and cheap and could also burn your car down. Proceed with CAUTION on #2.
-Daniel