Hi,

I have an jdm h22a engine and when I step on the gas the rpm guage goes down before it goes up. You can hear the engine losing air/pressure when the rpm goes down. It's much less noticeable when you step on on the gas pedal hard but it is very noticeable when your gentle on it. Any suggestions?

Thanks

 

It's idles quite well (steady)

 

Throtle posistion sensor maybe. bump

 

that was my first guess. I guess check the voltage on it. There should be a 5v reference, a ground and a signal wire. The ground should read very close to zero volts and the signal should be approx. .5v at idle and increase while you open the throttle and at WOT it should read around 4.45-4.7 approx. Make sure it increases while you open the throttle. If you need a wire diagram let me know ill see what i can do.

 

Often - someone will try to adjust the idle speed by moving the throttle cable tension instead of using the idle screw (recessed screw facing passenger side wheel well) as the idle screw isn't immediately apparent.

 

Hmmm... I just recently found that the idle screw on the TB was gone! But by luck I found it hidden in the bottom of the engine compartment. I screwed it back on all the way and back 1 turn. Could this be the problem? How much of a turn should it be?

 

i'm suprised that you didn't have an idle roll problem. correct me if im wrong some one. i believe you set the idle like this. unplug the iacv and crank the car. adjust the idle air screw until you have it idleing at the rpm u want. i think mine idles somewhere around 900 rpm. then turn off the car. plug the iacv back up. then pull your batt. cable off to reset the cel if it came on.

 

I had that idle bouncing problem where it went up and down continuously. Do I just take the hoses off the iacv or disconnect the unit it fully? Also The idle is first high to warm up the car (idle thermal valve) then it goes down to normal after it's warmed up. Can I still do this procedure??