sageuvagony

Hey guys, I thought now would be a good time to tackle this issue since gas prices are insane. A while back I decided to clean out the IACV since maybe it could have helped with gas milage since my car always ran rich, and after cleaning the IACV, my idle was jumping like crazy. Used new gasket and all. I drove the car for a few months like this. I knew the car was getting too much air.

During this period where my idle was bouncing, I had noticed my gas milage jumped up literally at least an extra 100 miles to the tank. I was lucky if I ever was able to hit 250 miles to the tank before the problem. During this problem, I was getting around 350 to 370 miles per tank which made me JUMP for JOY!!!!

Well I read up on how to fix bouncing idle by cleaning the FITV and screwing in that plastic thing. When I removed the FITV, the screw thing was almost completey out. I screwed it all the way back in like someone suggested, and idle and car returned to completely normal operation. The HUGE downside to this is that my gas mileage went back down to the usual 230-250 miles per tank.

It seems like both the IACV were plugged, and the FITV was screwed all the way out, therefore canceling out 2 separate problems. Cleaning out the IACV exposed the FITV problem.

I know for a fact that my car has ALWAYS run rich (tons of carbon soot crap on my rear bumper) and was confirmed by my mechanic. When I first bought the car I was lucky if I got 150 miles to the tank. Replacing the o2 sensor brought up gas mileage to 230-250 miles per tank. New ECU did not change anything.

I was so happy when my D15B7 blew (3 bad headgaskets) and was looking forward to the D16Y7's fuel economy. With the new D16Y7, NOTHING had changed at all with my gas mileage. Still sucks. So I KNOW the problem lies somewhere in my intake manifold. I'm using the bare D16Y7 with ALL of the D15B7 accessories (Intake manifold, ac, power steering, EVERYTHING)

I know that the extra air my car was getting was making things ALOT better, besides the bouncing idle. I checked TPS sensor and voltages are PERFECT closed and WOT.

This car has had MANY things changed such as wires, plugs, dizzy (I have 2,) air filter, just about anything you can think of.

My main question is this. Is there a certain amount I should screw in that FITV plastic screw thing? I believe that unscrewing it allows more air into the intake manifold.

Sorry for the long rant. Thanks guys!

Edit : The pic below shows what I mean by using all my original components. I KNOW the problem lies in the intake manifold somewhere!





Modified by sageuvagony at 2:42 PM 8/5/2008

sageuvagony

bumpness

batallic

i screwed it all the way to the bottom

B18CivicEJ8

x2. That's how it's supposed to be.

sageuvagony

*sigh*... this sucks... So to either choose between great gas milage or an annoying bouncing idle (embarrasing because of my exhaust)

z6hatchboy

try replacing the o2, and a valve lash adjustment. And check your vacuum lines, also the one that goes to the fpr.