Weird Idle Surge Issue

D15, D16, D17 and Mini-Me swaps
 Reply

Weird Idle Surge Issue

By TiggerDX
- Sat Nov 20, 2010 12:06 am #223683 So after I cleaned my throttle body and surrounding sensors I get a warm idel surge. The car starts and runs fine. Cold idle is fine.
After being driven when I put it in N or P the surge starts. It is a higher idle that drops briefly then back to a faster idle then drops again.
Since I have been dealing with the oil leak I haven't messed with it. Pulled the head off, took the intake manifold off. Cleaned everything inside and out. New gaskets for the head, intake, exhaust and surrounding areas.
Re-cleaned the sensors on the throttle body and reinstalled everything.
Surge is still there. It will go away when I disconnect the throttle angle sensor and plug it back in.

Took it for a 20 minute drive to make sure everything was working for the head removal and when I pulled back into the garage the surging wasn't happening. Thought maybe the drive had cleared it.

Here's the weird part.
When I turned off the head lights the surging started again. It would stop when I turned the lights back on (either parking or head lights)
Not sure if the lights draw enough power to cause the idle to increase above the range for the surge to happen.

94 DX with a D15B7

Anyway, any thoughts on what to check would be much appreciated.

Thanks,
Brian

By TiggerDX
- Sat Nov 20, 2010 1:01 am #223691 After further trouble shooting, when I cover the lower hole in the TB the surge stops. This leads me to believe it may be the FITV -( Fast Idle Thermo Valve) causing the issue. From my understanding there should be no vacuum in this hole when the engine is warm, but when I covered it, it nearly sucked the finger tip of my glove off.

Am I looking in the right direction?
User avatar

By Eg6H2D
- Sat Nov 20, 2010 3:23 am #223699 Good observation i was going to tell you to cover that with your finger. yea. a new one of those runs about 50 bucks at honda. :thumb:

By MG6
- Sat Nov 20, 2010 3:59 am #223704 you can always clean the FITV first before spending any money for replacement.

By TiggerDX
- Sat Nov 20, 2010 4:08 am #223705 It has been cleaned. That's what caused this in the first place. It idled fine before I took the TB off and cleaned it and the sensors.
I pulled it off and cleaned it again. I tried adjusting the adjustment screw (ring or whatever you want to call it)
I got it to the point where it is not creating a vacuum when hot, but was too hot to put the rear plate back on. I don't think it fixed the issue, but will know more tomorrow.

I am so tired of this car. After a week of redoing the head and sealing off everything I could, it is now leaking heavily again. Can't tell if it is the dizzy O-ring or the valve cover gasket. Both are new.
User avatar

By si-b16
- Sat Nov 20, 2010 4:42 am #223707 I'd Say it is a faulty tps (Throttle Position Sensor) Try Replacing that an see if that makes a difference, they don't cost much :)

By TiggerDX
- Sat Nov 20, 2010 8:38 am #223719 It doesn't appear to be a removable item and from what I understand it is a single unit with the Throttle Body.
 Reply
Return to D Series