IACV - Switched Multiple Units - Still CEL
04-28-2014, 06:33 AM
#1
IACV - Switched Multiple Units - Still CEL
JDM B18C-R
2001 ITR Chassis (01-1058)
Got heR running and all good to go but cant seem to get rid of a IACV check light. I was not having any kind of problem with IACV when I had this motor in my hatch 6 months ago, but when I did the swap into the ITR, it was coming up.
Figured no big deal, it happens sometimes I will swap it out for another unit I have in my garage that I know was working. Tried that unit and would not come on for say 15 minutes of driving and then come on. When the light was not on yet, there is a hunting idle and its all over the place. Sits at 1,200rpm then slow rev to almost 4k then back down to 2k then 1500. Then idle. Then up a little but not to 4k and then back down to 1500-2k.
Its not a fast burping hunt. Its slowly rising.
There is also a hesitation on deceleration. It feels like it is sputtering when I let off the gas. But as soon as the CEL comes on, this sputtering on decel and hunting idle goes away. CEL blinks 7 which is IACV.
I have changed 3 different IACV's into the car all eventually throwing a light. I tried to bleed any air out of the system but didnt change it much.
I looked into some threads and saw that the thermostat may be a culprit, and since I had been running really really cool I figured it was worth a shot. I changed the thermostat which emptied most of my coolant so I did a full refill again last night after changing it and letting it burp and whatnot. I also took one of the IACv's and cleaned the hell out of it while doing the thermostat so it was nice and fresh.
Now it seems the CEL for IACV comes on in the first 10 seconds or so of running. No hunt, no hesitation on decel, but light is on. Running a bit smoother and more up to spec with temps with new thermostat but still have a CEL for the IAC.
Is there anything else I can do to try to fix this? Our cars dont have a FITV so I cant clean or adjust that! I read pinching the PCV valve to see if there is a difference in the idle? Others have mentioned a vacuum leak? But I had smoke tested this motor previously and didnt see any leaks anywhere!! I ordered a new Hondata intake manifold gasket just to be safe.
Is there anything else I can dig into to try to find out whats causing this??
2001 ITR Chassis (01-1058)
Got heR running and all good to go but cant seem to get rid of a IACV check light. I was not having any kind of problem with IACV when I had this motor in my hatch 6 months ago, but when I did the swap into the ITR, it was coming up.
Figured no big deal, it happens sometimes I will swap it out for another unit I have in my garage that I know was working. Tried that unit and would not come on for say 15 minutes of driving and then come on. When the light was not on yet, there is a hunting idle and its all over the place. Sits at 1,200rpm then slow rev to almost 4k then back down to 2k then 1500. Then idle. Then up a little but not to 4k and then back down to 1500-2k.
Its not a fast burping hunt. Its slowly rising.
There is also a hesitation on deceleration. It feels like it is sputtering when I let off the gas. But as soon as the CEL comes on, this sputtering on decel and hunting idle goes away. CEL blinks 7 which is IACV.
I have changed 3 different IACV's into the car all eventually throwing a light. I tried to bleed any air out of the system but didnt change it much.
I looked into some threads and saw that the thermostat may be a culprit, and since I had been running really really cool I figured it was worth a shot. I changed the thermostat which emptied most of my coolant so I did a full refill again last night after changing it and letting it burp and whatnot. I also took one of the IACv's and cleaned the hell out of it while doing the thermostat so it was nice and fresh.
Now it seems the CEL for IACV comes on in the first 10 seconds or so of running. No hunt, no hesitation on decel, but light is on. Running a bit smoother and more up to spec with temps with new thermostat but still have a CEL for the IAC.
Is there anything else I can do to try to fix this? Our cars dont have a FITV so I cant clean or adjust that! I read pinching the PCV valve to see if there is a difference in the idle? Others have mentioned a vacuum leak? But I had smoke tested this motor previously and didnt see any leaks anywhere!! I ordered a new Hondata intake manifold gasket just to be safe.
Is there anything else I can dig into to try to find out whats causing this??
05-07-2014, 05:10 AM
#2
Re: IACV - Switched Multiple Units - Still CEL
Well amazingly enough somehow the culprit was my TPS sensor?
I changed my wiring harness due to seeing some hacks in the wiring and after doing that, I was getting a code for TPS signal instead of IACV. I tested my TPS unit and found that just the smallest touch would jump the signal at the plug from .66 to .04 and would also never hold a steady reading. Also opening the throttle to test 4.5V would only show small jumps in voltage, however upon releasing the throttle (even really easily) would change my at rest voltage reading again.
Changed out for a known working unit, re calibrated with ease now that i was able to get a solid a constant adjustable reading for voltage. Reset the ECU and performed the "Idle Learn Procedure" and have been good to go since. Rolled around about 50 miles last night with no issues.
Idk why the older harness was throwing a IACV code for the TPS having an improper signal, but it is good to know that this could be a possible culprit and something to check for future wrenchers.
I changed my wiring harness due to seeing some hacks in the wiring and after doing that, I was getting a code for TPS signal instead of IACV. I tested my TPS unit and found that just the smallest touch would jump the signal at the plug from .66 to .04 and would also never hold a steady reading. Also opening the throttle to test 4.5V would only show small jumps in voltage, however upon releasing the throttle (even really easily) would change my at rest voltage reading again.
Changed out for a known working unit, re calibrated with ease now that i was able to get a solid a constant adjustable reading for voltage. Reset the ECU and performed the "Idle Learn Procedure" and have been good to go since. Rolled around about 50 miles last night with no issues.
Idk why the older harness was throwing a IACV code for the TPS having an improper signal, but it is good to know that this could be a possible culprit and something to check for future wrenchers.
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