Lots of Searches, Tried everything, still high idle

Benzilla19

New Member
I am brand new here on the forum but have spent much time browsing around as a guest, doing searches to solve my issues and trying what oher members have suggested. I thought it was time to say hi and ask for some additional help from the senior Integra owners/mechanics.

I recently bought a 1990 Integra, It is pretty ricey with a full kit but the price was right at 500 bucks as a cheap daily driver. The car has about 190k B18A1 with intake, header, and exhaust, other than that it appears to be all stock. When I got the car it had some bad hesitation and idle issues. I believe I have resolved the hesitation issue via fixing the timing which was off a few teeth. I however have not been so successful with the idle. The car starts a bit rough but does start each time. It idles up to about 1500-1800 when cold however to the best of my ability I have not been able to get it under about 1200 when completely warmed up. I have replaced the throttle body as the one on the car was missing the plate stop screw and the idle adjustment was stripped, I have completely taken off cleaned and tightened the FICV. I have cleaned via instructions and tried 3 different IACV motors, I have replaced all my vaccum lines, I have tried to spray carb cleaner everwhere and never get a different a rev or change in idle to signify a leak, I have replaced my PCV valve, I replaced the thermostat drained the coolent, replaced and left cap off while warming all the way up to remove bubbles. I have even tried a different ECU.

I did notice that per the instructions for setting the base idle as soon as I unplug the IACV I get a check engine light but the strange thing is it idles perfect wtih it unplugged, and like I mentioned I have tried 3 of these things all cleaned out and tested with the 12 volts to make sure they click. Am I missing something? something with the cooling setup? For some reason the owner before me messed the cooling gauge up. They put an overlay on the cluster and now the coolent gauge needle is gone. They installed some aftermarket gauge and for some reason bypassed the fan control via sensor and ECU in favor of a toggle switch. I have plans to repair this but have not as of yet. Already bought another cluster, the original connector for the fan and found a broken wire on the fan relay which is why they may have done this in the first place.

Sorry for the long first post but hoping someone out there has had the same issue and might be able to help.
 

jdean41

New Member
check your throttle cable, recheck the base idle screw on top of the throttle body, and clean the FIT valve that is located under the throttle body. 1200 is not a bad idle if it is smooth.
 

Benzilla19

New Member
Awesome thanks for the ideas, checked the throttle cable and it is fine. Idle adjustment screw is all the way in currently but when I did the base timing it seemed to idle at the specified 650rpm at about a turn and a half out. I am not familiar with the FIT valve however, I will check on that next.
 

Benzilla19

New Member
Thank you for the link, there is some great information in there. As mentioned above I have had this completely off the car, apart and cleaned really well. When re-assembling I was sure the screw the white portion all the way down.I did not check again since doing this but as I understand it the lower hole in the throttle body which feeds this valve should have no suction or very little once at running temp. I will verify this. The link you suggested did have some good information about the IAC taking signals from different sensors to adjust load. One of the sensors mentioned was the Engine Coolant Temp (ECT) Sensor, I wonder if this got bypassed when the previous owner messed with the cooling system, maybe this is why it never idles down any further?
 

Benzilla19

New Member
Well problem seems to have gotten worse, drove it today, of course idle was too high between 1200 and 1500. For some reason when I got home it would not idle below 2k. I removed the rad cap to make sure there were no more bubbles, and did the base idle/reset computer again but it made no difference. From my research it seems everyone says if it has a high idle after warm and putting your finger over the top hole makes the motor die it is the IACV. I swapped it with the last one I had gather from the junkyard (of course after cleaning it really well and letting it dry and testing the valve with the 12volt procedure) Let it warm all the way back up and vented the coolent bubbles. It seemed to idle down to about 1200 unit the first time I touched the throttle than it shot up to 2k and now it just surges between 1500-2k this idle stuff is very frustrating with this motor and it really does affect the smoothness and drivability, especially the surging. I cant believe I would have 4 bad IACV motors so it must be somthing else.
 


Rich-PMS

New Member
Take the 2 8mm bolts off the FITV, and make sure the white piece inside is screwed all the way in. Should solve your problem.

Also- unplug your iacv, it should idle at 800ish rpms. If that does happen then your iacv is NOT the problem
 

leftyfork

New Member
It sounds like your throttle plate is open too far, or you have a vacuum leak. To test, You can remove and plug every single vacuum hose on the intake except for the one leading to the MAP sensor and the fuel pressure regulator. The map hose is located at 1 o'clock on the throttle body. Get some plugs at the auto parts store.
Your throttle plate must be mostly closed. You didn't turn the little allen screw with the lock nut to open it did you? The throttle plate should be completely closed, but not so closed that it binds in the throttle body at idle. Start there, then adjust your idle by unplugging the iac valve and setting it with the base idle screw on top of the throttle body.
 

96IDtegSS

New Member
same exact problem here, ive done everything you have, yet it helped slightly with a throttle position sensor... new map sensor iacv vaccuum lines coolant throttle body intake manifold you name it ive tried it and its beyond frustrating. just know youre not alone
 
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