high idle on 99 SL1
alross10
10-15-2004, 12:20 AM
My wife 99 SL1 started idling at around 2000 RPM and the check engine light came on at around the same time. I changed the plugs, the IAC, the TPS, and the check engine light went off but the idling problem remained. The idle screw is all the way out and I have run out of ideas. Anyone with any idea?
sierrap615
10-15-2004, 12:44 AM
um best not to mess with the idle srcew(i've done it my self, bad things happened)
did you happen to get the code?
manual or auto trans?
ever replaced the ECT?
do this: go out and buy a can of sensor-safe carb and choke cleaner, spray it into the throttle body, the carbon build-up not leting the throttle plate close can act like a vacuum leak. next, spray the carb cleaner around the intake manifold gasket with the engine running. the later SOHC like to suck the gasket in, if the engine bogs down, there is your problem. the next step would to be remove the EGR and clean it out to, but i would rather have the code before doing any more.
did you happen to get the code?
manual or auto trans?
ever replaced the ECT?
do this: go out and buy a can of sensor-safe carb and choke cleaner, spray it into the throttle body, the carbon build-up not leting the throttle plate close can act like a vacuum leak. next, spray the carb cleaner around the intake manifold gasket with the engine running. the later SOHC like to suck the gasket in, if the engine bogs down, there is your problem. the next step would to be remove the EGR and clean it out to, but i would rather have the code before doing any more.
shamefoot
10-15-2004, 12:46 AM
Don't do like my little brother and spray about a can and a half worth of carb cleaner in your intake ( stuff is not flamable ) gunked his poor car up big time.
sierrap615
10-15-2004, 11:59 PM
no, clean the intake with the engine off, and just do quick sprays when checking for vacuum leaks.
Automotive Network, Inc., Copyright ©2026