rpm drops when ctuch is in
rpm drops when ctuch is in at any speed when i put the clutch to the floor my rpm will drop to about 500 to 600 then jump up and down till it settles at 1000 again. but my problem is when it drops like that i get no brake boost could this be fixed with a tune or is it something else. oh and the car is tune just enough to drive
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
when did this start? Did you just recently put that 240/244 cam in? was it tuned after the cam was installed?
With that large of a cam your vacuum assist for the breaks is going to be diminished over stock by quite a bit, but w/the RPMs dropping like that it does sound like a tuning issue (when clutch is pressed in, it removes a bunch of load from the engine so the pcm needs to compensate for this loss of load)
With that large of a cam your vacuum assist for the breaks is going to be diminished over stock by quite a bit, but w/the RPMs dropping like that it does sound like a tuning issue (when clutch is pressed in, it removes a bunch of load from the engine so the pcm needs to compensate for this loss of load)
its been like that since the motor has been built but for right now it has a conservitive tune. but it brakes real good at 1000 and up my idel is at 1000 so a full tune should fix that? or is there anything that i can do to fix it?
Last edited by Disturbed Bird; Jan 27, 2007 at 05:59 PM.
FormerVendor
Joined: May 2006
Posts: 187
Likes: 0
Should be able to be significantly improved with a tune. Is this only when in motion or also when the car is sitting still? Do you have any tuning/scanning software? Your tuner needs to get the base airflow and timing correct. This will improve your situation, and then the adjustment tables (like Follower) can fine tune the rest of the way.
no dont have a tuner but its only when im put in the clutch while moving it will drop till i come to a complete stop then rise back to 1000. and only does it while im in motion not when im standing still
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TECH Fanatic
Joined: Aug 2005
Posts: 1,691
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From: Sunny London, UK
PCM holds idle higher when car is moving to assist gear shifts and matching rpm's etc.
There are tables to control the amount of air the IAC allows in. You might need to raise the airflow to prevent idle droping.
There are different values depending if you are in Park or Neutral (PN) or In Gear (IG)
So pushing in the clutch might be shifting you to the other table and hence lower value.
Have you got a tune tool?
There are tables to control the amount of air the IAC allows in. You might need to raise the airflow to prevent idle droping.
There are different values depending if you are in Park or Neutral (PN) or In Gear (IG)
So pushing in the clutch might be shifting you to the other table and hence lower value.
Have you got a tune tool?
