Honda Car Forum

After I swapped my Intake manifold, my car starts to bug down on all gears.. And the idle is rough like it seemed to be having a hard time breathing that it want to kill itself.. I got the other manifold from the junkyard, so it might just be dirty? Or could it be sucking air or vacuum leak? I think I did everything right and I don't understand why it bugs down like that..































Any thoughts about this?

Does you idle go up and down?

you need to check everything between the throttle body and the cylinder head for a vacuum leak. the car boggs down because there is too much air for too little fuel; the air is un-metered when this happens which means your addiitonal air is coming in after the throttle body. it can be at the bellows, the throttle body gasket, the intake gasket or any of the rubber hoses that attach to the intake, though the smaller hoses won't usually affect it as much as a large hose (for example, the large vacuum hose for the power brake booster would cause this).































my suggestion is to get a clean spray bottle, like one for 'Windex". fill the bottle with water. then start the engine and let it run. when the engine idle starts to 'hunt' or surge up-and-down start misting the area around the cylinder head to intake. if the idle starts to smooth out, then you have a leaking intake gasket as the misting water will seal the gasket temporarily. if the idle is still erratic, start spraying around the throttle body, then move to all the hose connetions.































the one thing that is unrelated to the gaskets that may be causing your problem would be an EGR valve that is hung open. that would affect the idle and the performance of the car under 2500 rpm. if the car is bogging down over 2500 rpm the EGR isn't likely to be your problem as that is when the valve is normally open.































hope that helps