psychokilla

I have a 90 CRX hf stock and when i turn it on it runs fine. after its warmed up and i do a complete stop the rpm goes around 300 or less. Also, when i press the breaks the rpm drops even more making my car shake. It has not done it lately but there have been times when i switch gears it hesitates for a second then i feel the force of an hf lol.

Not sure if this will help but when I did the smog it only passed with the help of the smog shop. The NOX was exactly at max. I changed the oxygen sensor after and had done a plug and wire change as well as an oil change and fuel and air filter prior to the smog. I also changed the rotor (have not changed the cap because they didn't have it in stock at that time). No code is given by the ecu.

Things I think could be wrong with the car are; catalytic converter (if anyone knows where i can get an OE let me know), grounding, ecu, injectors, and/or a leak in the hoses.

RanCRX

Should be the same with d series. Try grabbing a screw driver, turn on car, wait for car to reach normal temps, open your hood. There will be a golden flathead screw on the upper portion of the throttle body, turn cloclwise for lower idle, counter clockwise for higher idle. It is sealed by silicone, once you free the screw from silicone, reapply silicone once you have your idle at the position desired, or engine will shake the screw loose or tight

psychokilla

I have tried to adjust it before but it did not help. Left it on until it got warm and adjusted it but did not help after a while it went back to how it was.

Lobeau

I have the same issue with my D15 carbi. Once the car reaches a certain temp the idle drops to about 400 rpm. I have no idea about carbi's so any advice would be great.

RanCRX

I would look into your IACV, Idle Air COntrol Valve, and then your Fast Thermal Idle Valve. In the inside's of them, they have adjustments, I would research here on HT on a DIY of how to do it.

Otherwise, try unplugging your IACV when your car gets to normal operating tempature (it will turn on engine light) then adjust your idle screw until your idle is at 500rpms. Turn off your car, plug back in your IACV plug, turn car back on, should idle at or near 750rpms. If you still have engine light, turn off car, disconnect neg battery cable for 30 seconds, then plug back in your neg battery terminal, it will go away

RanCRX

When doing throttle screw idle adjustments, the "standard" is to unplug the IACV at a certain point. Just hopefully the car doesn't shut off on you since it is already at low idle

psychokilla

I will do that today, hope it works. I already cleaned it when I started having the issue. Thank you for.the advice much appreciated. What do you mean unplug the IACV at a certain point?