Engine won't idle
08-10-2007, 07:06 AM
#11
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Speaking of cleaning all this out... Because (as I mentioned before) I do not have a full set of tools with me in LA, I would prefer to keep the disassembly I do to a bare minimum. What are your thoughts on spraying some carb/choke cleaner into the intake while the car is running to clean out whatever may be left in the IACV? Bad for the engine? I realize some soot will get dislodged and go into the motor this way, but from looking at what came off the TB, I would say it's all very fine particulate and probably not going to do any harm.
08-10-2007, 07:54 AM
#12
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I did that when I seafoamed my car couple of months back (through the throttle body and through one of the vacuum tubes). I was surprised at how dirty the inside of the intake manifold was. It ran SOOO much smoother after the process.. ( I didnt put the seafoam in the gas tank or in the oil, just the intake.. i used a little under half the container).. Not sure about the carb cleaner, I'm assuming it would be fine. good luck
08-12-2007, 06:48 PM
#14
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Originally Posted by Slows2k,Aug 9 2007, 07:45 PM
Most likely a Faulty IAC.
You can unbolt it from the intake manifold and spray it out with carb cleaner. If the idle comes back you're lucky. usually they will start idle surging and then you have to replace it.
You can unbolt it from the intake manifold and spray it out with carb cleaner. If the idle comes back you're lucky. usually they will start idle surging and then you have to replace it.
Today (fourth day) I start the car, It hiccups and starts the up/down idle and the CEL comes on. It's still just the one DTC 1519, and the freeze frame say's it happened at 0RPM. I had to re-start it 3 times before it would cease the up/down crap.
I had already read in couple threads where you said once it codes or actually starts the up/down idle as opposed to just a dropping idle, the IAC would most likely need replacing. I had to try anyway, it was free and now I know I can replace it myself. I was hoping I had gotten lucky and dodged like $140.00 bullet. It does not appear so. Looks like I'm off to Honda parts tomorrow.
I still haven't pulled the kick panel to check the wiring at the ECU. Also one of the troubleshooting steps involves swapping in a known good ECU for testing. It's the one step from the troubleshooting procedure I can't do.
So I guess my question is: from your experience do you think it is most likely the IAC? Assuming the wiring checks out OK at the ECU also. Have you seen a failed ECU cause this? Any other tips you feel like offering?
Thanks.
EDIT: To remove and clean the IAC all I needed was:
3/8 ratchet with a 10mm 6pt. normal depth socket.
Pliers for the little hose clamps.
Paper towels (like a teaspoon of coolant spills when the upper small hose is removed and again when the IAC itself comes off the intake manifold)
spray bottle with water (used it to dilute the few drops of spilled coolant I couldn't get at)
Other stuff I used:
Shin Etsu (on the boot for the IAC 3p connector and the IAC gasket/o-ring itself)
Silicone Dielectric (on the contacts for the IAC 3p connector)
WD-40 (cleaning the IAC, much less effective than throttle plate/carb cleaner)
Honda Throttle Plate Cleaner (cleaning IAC, worked really well)
Rubbing Alcohol (to remove any WD-40/carb cleaner residue from the IAC chambers and groove for the rubber gasket)
Q-tips (use good light and magnification if necessary to make sure no fibers remain in IAC after cleaning)
Remove the 3p connector by locating the clip release located on the bottom of the 3p connector. Squeeze the clip release on the 3p connector through the rubber protective boot. Wiggle and pull the 3p connector by the boot/connector not the wire harness, while squeezing the release clip through the boot at the same time.
I found that tip from Billman250 in another thread.
I pulled the higher small hose off the IAC before I un-bolted it. I slid the clamp back on the lower small hose, but un-bolted the IAC from the manifold before removing the lower hose. It's a little awkward but once the IAC is un-bolted from the Intake Manifold it can be dropped slighty down and back (toward cabin firewall) and removed from the second/lower small coolant hose without disturbing the throttle cable or bracket.
08-14-2007, 11:07 AM
#18
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Rev, check the TPS on the TB (sounds like I'm being a smart-ass... "Excuse me, but if the VP is such a VIP, then shouldn't we keep the PC on the QT? Cause if it leaks to the VC, he could end up an MIA and then we'd all be put on KP.").
MY TPS showed erratic voltage readings when sitting at idle... I think the wiper wore too much of the resistor away in that spot (too much time tapping the pedal while sitting at stop lights?
). It drove fine, and the engine sounded fine while the car was moving even while out of gear... once the speedometer hit 0, though, it chugged and died unless I gave it a continual touch of gas.
My only solution was to replace the entire TB as no one had a replacement TPS at the time. 45 minutes under the hood fixed it right up.
MY TPS showed erratic voltage readings when sitting at idle... I think the wiper wore too much of the resistor away in that spot (too much time tapping the pedal while sitting at stop lights?
). It drove fine, and the engine sounded fine while the car was moving even while out of gear... once the speedometer hit 0, though, it chugged and died unless I gave it a continual touch of gas.My only solution was to replace the entire TB as no one had a replacement TPS at the time. 45 minutes under the hood fixed it right up.
08-15-2007, 07:36 PM
#19
Have you tried doing nothing? 
Seriously, sometimes the ECU gets a little wacky (yes, that's the technical term ) and it just needs to re-learn how to idle. This is a known and very common issue. So, when you come to a stop and the idle dips, DON'T give it gas. Let it stall if necessary, then restart it. Be patient; might have to do this several times. About a year ago I had to let my car stall 4 or 5 times on my way to work; eventually it learned, and by the evening commute it was idling flawlessly, and has ever since.
Seriously, sometimes the ECU gets a little wacky (yes, that's the technical term
) and it just needs to re-learn how to idle. This is a known and very common issue. So, when you come to a stop and the idle dips, DON'T give it gas. Let it stall if necessary, then restart it. Be patient; might have to do this several times. About a year ago I had to let my car stall 4 or 5 times on my way to work; eventually it learned, and by the evening commute it was idling flawlessly, and has ever since.
08-16-2007, 06:47 AM
#20
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John - I think you're basically right (and it is indeed idling just fine now). I believe the reason WHY it's had to relearn is for the reasons everyone else is getting to - dust in the MAP pathway and the IACV. So I do still plan to do a cleaning when I have time, but it's a low-priority for the reason you stated.