High RPM at idle. 1200 rpm?
11-07-10, 10:32 AM
#1
High RPM at idle. 1200 rpm?
Hey folks
Just made a big service on my 91 LS. Seafoam. Dif oil, gear oil, engine oil + filter. valve cover gaskets. ngk sparkplugs and wires.
now i also changed the water temp sensor and the little oil filter or what it is on top of the right valve cover.
I disconnected the battery and now the car runs better than before, but now in PARKED its on 1200 RPM. Isnt that too high?
When in DRIVE its about 800rpm so that should be fine right?
When i disconnected the intake i discovered alot of carbon build up on and around the throttle. I kindda cleaned it a little but i was a little in a hurry to get everything assembled so i could drive home in the car so i didnt have time to do a complete clean.
i noticed that because i cleaned the throttle it now at closed state do not close 100%. i can see light through at the top and bottom. is this normal or should i be tight? this is maybe a milimeter or less but is it enough to make this high rpm when Parked?
I hope someone have som answers. I would like to have my LS as perfect as possible
Just made a big service on my 91 LS. Seafoam. Dif oil, gear oil, engine oil + filter. valve cover gaskets. ngk sparkplugs and wires.
now i also changed the water temp sensor and the little oil filter or what it is on top of the right valve cover.
I disconnected the battery and now the car runs better than before, but now in PARKED its on 1200 RPM. Isnt that too high?
When in DRIVE its about 800rpm so that should be fine right?
When i disconnected the intake i discovered alot of carbon build up on and around the throttle. I kindda cleaned it a little but i was a little in a hurry to get everything assembled so i could drive home in the car so i didnt have time to do a complete clean.
i noticed that because i cleaned the throttle it now at closed state do not close 100%. i can see light through at the top and bottom. is this normal or should i be tight? this is maybe a milimeter or less but is it enough to make this high rpm when Parked?
I hope someone have som answers. I would like to have my LS as perfect as possible
11-07-10, 02:06 PM
#3
If your throttle butterfly is not completely closed at idle the idle speed will be higher than normal so give it a complete clean.
The tutorial below shows how
http://www.lexls.com/tutorials/EFI/throttlebody.html
Also bear in mind if the battery has been disconnected the ECU has to relearn engine settings.
The tutorial below shows how
http://www.lexls.com/tutorials/EFI/throttlebody.html
Also bear in mind if the battery has been disconnected the ECU has to relearn engine settings.
Last edited by steve2006; 11-07-10 at 02:07 PM. Reason: addition
11-08-10, 08:29 AM
#4
Pole Position
Idle at 800 RPM is still too high. Should be around 600. When you did the partial cleaning you might have loosened up some carbon chips (tiny) which could be what is holding the throttle open a bit. As Steve said, do a full clean on it. That should clear it up and you'll be fine. Or because you were in a rush, did you disconnect a vacuum line which you forgot to reconnect? I also agree with python about spraying the carb cleaner to see if idle changes.
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