LOW idle RPMs

[ktienation]

I have searched the forum but have not found any topics related to fuel injected engines.

When the engine is cold, the idle rpms seems normal (~1800), however when the engine get well warmed, the rpms start to drop to about 1400 even 1200 rpms (where there should be 1600 accorind to the manual). What might be the reason of this? Weak battery should not cause such things, or am i wrong?
P.

[sklnzl]

You shouldn't just look at the tachometer reading to know if the idle rpm is normal ,as the analogue tachometer is never a precise instrument , sometimes you should also listen listen to the engine idle sound which should be smooth .

[ktienation]

sklnzl I am aware of that:) However, i think that 1200 indicatend will be anytway less than 1400 true rpm. And mine tends to show even 1200 sometimes. Moreover, when the rpms drop that much i can see the lights to dim and thats for sure a prove, that the rpms are too low as the generator is not able to produce enought energy.

[windwheeler]

Are you inclined to remove the seat and storage bin and get to the fuel injection? 

On top sits the MAP sensor.  it has one screw.  Mark the present position of the MAP sensor so you could go back to that at any time. 

While the engine is running and warm turn the MAP sensor in small increments either direction (trial and error) until the the idle rpm goes up.  Do not put the storage bin on, just the seat and go for a quick spin and see if all works well and it keeps the higher idle rpm.  If you are happy with it put it back together, otherwise try a few more different positions of the MAP sensor.

You should do/become familiar with the (simple) reset procedure of the TPS/throttle body just to make sure to clear incorrect or garbage information in the FI computer.  It is a good idea to do do this anyway from time to time.  You may actually start to do that first and see if that helps your problem already.

[Goodrich]

Sorry...wrong thread

[ktienation]

windwheeler, the reset help indeed. Thank you a lot for your advice.
Peter

[windwheeler]

windwheeler, the reset help indeed. Thank you a lot for your advice.
Peter

Glad to hear that Peter!  Thank you for the feedback.