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Discussion Starter · #1 · (Edited)
Hey guys!

First off thanks for taking the time to read my post, I've read for hours on this forum about this issue just need clarification on what I've got going on. Originally before I started working on the car it had a high idle but it wasn't bouncing.

Here's a video of the idle.

My question : Is my Brand new IACV bad? If so where do you recommend I get another one.

I have the bouncing Idle issue, I've changed quite a few parts :

Parts Replaced / Things Done :
Bled the Coolant system multiple times getting strong stream from bleeder screw.
IACV New $27 cheap Ebay part originally for Honda Accord everything fits up the same just the electric connector is in a weird place.
Adjusted the FIV it's tightened up, haven't tried the cardboard trick yet.
Adjusted Valve Clearance
Valve Gasket Replaced
NGK Spark Plug Wires
NGK Spark Plugs
New Fuel Filter
Oil Change
Transmission Fluid Change
I sprayed down all areas with carburetor cleaner to see if there's a vacuum leak of some kind. Didn't see any. Sprayed intake manifold pretty good no changes in idle.
Engine is fully warm during all this testing.
IACV Ohms Reads : 14.3 Ohms (saw online it should be between 8-15 ohms)
Checked terminals continuity with good ground. There is no continuity so that's good.

When I disconnect the IACV the car idles very nicely. I Jumped the service port connector and set the ignition timing at 15 off center. And adjusted idle, idles nicely around 750-800 rpm at warm temperature. When I reconnect the electrical connector to the IACV idle goes back to bouncy up and down. When I disconnect there's one long light followed by 4 blinks of the check engine light. indicating code 14 for the IACV. If it's connected there's no check engine light codes. There is an adjustment screw for the IACV I had it all the way in, bouncy idle I backed it almost all the way still the same. I'm not sure where that's supposed to be. Here's a pic of that.

Automotive fuel system Motor vehicle Automotive tire Automotive design Auto part


Also have my garage fan running on high because the car fills my garage with the strong smell of exhaust fumes and gas, could be running rich? Seems little worse when I disconnect the IACV electrical connection. Here's a photo of my engine bay.
Motor vehicle Automotive air manifold Vehicle Hood Car
 

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Discussion Starter · #3 ·
I just had to say this. My prelude has the same air boot rip for the air cleaner system. I see you covered it up! I used electrical tape on mine. My prelude has a bouncy idle too but it is only when you rev the car before it gets warmed up or if it is like 40 degrees outside and you put it in drive then it will bounce for a few seconds and then stop. I just haven’t got around to fixing it yet.
Yeah I covered it with duck tape but realized it's not super important since nothing is measured before it. I'll have to cover it up with something black lol. Yeah I don't know what's up with my car. Drives pretty good with IACV disconnected but don't think itll be good long run. Gotta figure this out.
 

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Discussion Starter · #5 ·
It's seems that the iacv is the problem still.
Follow the tech manual procedure for the testing.
But also replace it with the OE one.

Hey Thanks for responding and yes after doing some more diagnosing and getting a original DENSO part from the junkyard it's idling beautifully!
 

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Discussion Starter · #6 ·
Thank you to everyone who responded and read my post.
Here is the update with the solution :

Replaced IACV (Idle Air Control Valve) with genuine part from the junkyard. Denso Original Part from a 1990 Honda Accord since they didn't have any preludes. It fits the only bad part is the electronic connection is at a weird angle that makes you need to disassemble the plastic housing on the wiring going to fuel injectors just have to unclip the plastic rail and then you can slide the connector underneath it and between it. Also when I got the idle air control valve it was very clean inside but I cleaned it more with carb cleaner making sure to keep the motor upward so the cleaner doesn't go in there. Also sprayed a few spritz of QD Electronic Contact cleaner on the electronic pins for the connector. Here is a video of the vehicle idling now and we have no check engine lights. Beautiful!

FYI I am touching the throttle at times so if you see RPM change that's just me.
FYI Car is from Canada so in KM not Miles. So less miles than that. : )

 
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