Hows everyone doing? I'm new here. And have a 96 civic with a weird rpm problem. I fixed the Idle fluctuating problem which was a bad intake manifold gasket but now I have another problem. When I tap the throttle in neutral the rpms go up then slowly drop to 1000 then rise up to about 1250 then back to idle at around 850.. Same thing kind of happens when im driving and push the clutch in and coast but when I'm coasting the rpm stay at 1500 then when i stop it does the weird idle thing.

 

Dont think This is a problem my 04 civic dd dies this also as long as when the throttle is closed it idles properly you should be alright. And if it is worse than what's stated in your post make a vid that will help diagnosis.

 

it seems to run ok while idling. but not perfect. I would love to have it running smooth so I can start the body work. I was thinking it maybe the TP sensor, the throttle body, or even the throttle body gasket. I have another throttle body but need to buy a TP sensor for it and new gasket. just trying to save every dime possible so I can put it toward my paint.

 

IACV is dirty clean it as it controls the idle
and will cause idle to climb up n down

 

I have 2 IACV's and cleaned both. It still does it with either one on.

 

try carby cleaner and spray around vac points for leaks

 

I'm thinking there might be a small leak somewhere. But I sprayed throttle body cleaner all around. thats how I found the leak around the intake manifold gasket. I will try to make a video if that would help

 

Its got worst now. when I tap the throttle or sit at a stop light/Sign the the rpms will raise then slowly drop then go up and down between 1000-1300 3-10 time then settle at around 850. and when i Parked it at my house it did it for like 10 min. then it just went to idle. also it seems I have a slight tick around the intake manifold or injectors. Its sounds slightly louder then the tick from the injectors. my friend says it sounds like a loose lifter but wouldnt the noise come from around the valve cover