HondaCivicForum.com - 98 Honda Civic DX 1.6L Surging Idle

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Quote:

Originally Posted by RonJ (Post 787508)

Usually not.

Go ahead and check output voltage just to verify. If it's fine, then Ohm test it.

OK, I will check the voltage and let you know. Thanks

Quote:

Originally Posted by Drewzo (Post 787509)

OK, I will check the voltage and let you know. Thanks

Ok, I checked the voltage. It's .48 closed and 4.7 fully opened. There was a smooth transition from close to open too. I don't know how to check the ohms though. The signal wire was reading 5.4v from the ECU.

You should measure 500-900 Ohms between terminals 1 and 2, and 3600-5400 Ohms between terminals 2 and 3.

Quote:

Originally Posted by RonJ (Post 787533)

You should measure 500-900 Ohms between terminals 1 and 2, and 3600-5400 Ohms between terminals 2 and 3.

What terminals are you talking about?

Quote:

Originally Posted by Drewzo (Post 787534)

What terminals are you talking about?

Stare at the diagrams I posted. THE SENSOR TERMINALS.

Quote:

Originally Posted by RonJ (Post 787535)

Stare at the diagrams I posted. THE SENSOR TERMINALS.

Oh, ok. I didn't see the attachment. I will measure the ohms and let you know. Thanks!

Quote:

Originally Posted by RonJ (Post 787535)

Stare at the diagrams I posted. THE SENSOR TERMINALS.

Sorry it took so long to respond. I couldn't figure out how to read the ohms on my meter. I went to the junckyard though and bought a new throttle body, with a new TP and MAP sensor. Same thing happens. The code goes away for a day or two and returns. I've also clean my PCV valve and run Seaform through the intake system again. I've bleed my coolant system several times, and can't find a vaccum leak. The surging idle goes away when I adjust the idle screw in the TB, but eventually the code returns (p0505). I've also had the cylinder 1 misfire code pop up once or twice (p0301 and all cylinder misfire p0300)

Quote:

Originally Posted by Drewzo (Post 787337)

I have a 98 Civic DX that has a surging idle. The CEL code is P0505. I cleaned the throttle body and IACV several times and bought a used IACV at the junkyard; still didnt work. I bought a new IACV, the problem was fixed for a few days and now has gone back to surging. I have checked for vacuum leaks and bled the coolant system. I replaced the ECT because someone told me that could be a problem. The idle problem only starts when the car warms up. If I remove the TPS and MAP sensors, the problem stops. Obviously I get two new codes once I pull the sensors. If I clear the codes while the car is idling, it starts surging again.

I also have another problem that I'm not sure if its related or not.
While I'm driving, if I let off the gas while in gear, the car jerks. When I push the gas pedal again it jerks as well. It doesn't happen all the time and only happens when I let off the gas and initially push the pedal. I have replaced the engine and trans mounts.

I would appreciate any help, Thanks.

hey ive been running the same year and model for 2 years now had the exact same problem theres an easy temp fix you can use to check if its your cad converter which confused me at first but i spent enough time looking under the hood i found my problem your cad may have a crack in it located close to the oxygen sensors most likely one or the other. apparently its a common problem. but if you have any experience welding then theres a simple way to check just be sure to disconnect your battery. but i went out and bought new oxygen sensors because that was the only code reading and my cad was shot but i notice a crack running almost straight up to the sensor which i welded and this fixed the light on my dash for 3 days so i cracked the hood to see it cracked again. this is because the cad is made of magnesium i believe and the weld didnt bond well. and my car showed the exact symptoms your did so possible just a cad converter and/or Oxygen sensor replacement now my car run my efficient and i even think it brought me back some well need horsepower.