944 Funny idle, any ideas?
05-02-2008, 03:09 AM
#1
Instructor
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944 Funny idle, any ideas?
So I have an 84 944, 169 xxx miles on it and still running strong. Its got an issue that has been bugging me for a while though.
When it starts up, even on really cold days (snowy, icey, etc.) it idles quite low, like in the 900-1000 range, but only after it warms up does it start idleing a bit faster (1100 or so). Also, when you tap on the gas and then let off all the way, the rev drops down to the point where the car shudders and sounds like its gonna die, then comes back up to idleing. Car has never died on me, but it definitely makes the car seem more rough than it should be.
Anyone have any ideas on what the issue could be? I took it to a mechanic once, and he said thats how all the 944s were, but I'm curious about other people's experience.
Also, I've noticed that the idle fluctuates a bit, and the engine has little spurts of sounding like it occasionally misfires (?) -> it'll be idleing, then it'll drop down slightly, get rough, then come back up again. Very brief, but noticeable under careful inspection.
???? Anyone have any ideas?????
When it starts up, even on really cold days (snowy, icey, etc.) it idles quite low, like in the 900-1000 range, but only after it warms up does it start idleing a bit faster (1100 or so). Also, when you tap on the gas and then let off all the way, the rev drops down to the point where the car shudders and sounds like its gonna die, then comes back up to idleing. Car has never died on me, but it definitely makes the car seem more rough than it should be.
Anyone have any ideas on what the issue could be? I took it to a mechanic once, and he said thats how all the 944s were, but I'm curious about other people's experience.
Also, I've noticed that the idle fluctuates a bit, and the engine has little spurts of sounding like it occasionally misfires (?) -> it'll be idleing, then it'll drop down slightly, get rough, then come back up again. Very brief, but noticeable under careful inspection.
???? Anyone have any ideas?????
05-02-2008, 10:58 AM
#4
Rainman
Rennlist Member
Rennlist Member
warm idle should be between 900-1000RPM...cold is usually 700 or 800.
the stumble is the result of the programming of the computer, when you let off the gas there is a fuel cutoff which was programmed too close to the idle speed (somewhere around 1300RPM) which makes the engine shudder. if you get a chip or switch to a later computer/AFM this is eliminated.
theres a nut on the top left side of your throttle body. turn it like youre tightening it to lower idle speed.
the stumble is the result of the programming of the computer, when you let off the gas there is a fuel cutoff which was programmed too close to the idle speed (somewhere around 1300RPM) which makes the engine shudder. if you get a chip or switch to a later computer/AFM this is eliminated.
theres a nut on the top left side of your throttle body. turn it like youre tightening it to lower idle speed.
