B16A2 IACV issues

[Sparky94]

So when I bought my car the idle jumped from 1000rpm up to 1500rpm and kept repeating. I took my iacv off and cleaned it, I made sure it was super clean before I put it back in. It was fine for about 3 days and now it's doing it again. But if I tap the gas pedal, it stops, everytime. Also, when I start my car it's a rough start and idles around 2000rpm. Any ideas on what's going wrong? Anything would be helpful!

 

[coryrayd]

I am having the exact same issue with my civic 2000 dx. When I start the car it will rev up and don constantly. If I leave it idling it will eventually stop and go back to normal. Recently it seems to have gotten worse. Same thing happens when I start the car, Revs up and down. I start driving without touching the gas its moving faster than it should. And now when I am going slow it will chug as if I am hitting the gas pedal in little spurts. Sometimes it will stop. Someone did tell me its a air control valve issue. I have a CEL code 8 and 9 top dead center and the other code I forgot. Any help for us guys would be nice,

 

[RonJ]

I am having the exact same issue with my civic 2000 dx. When I start the car it will rev up and don constantly. If I leave it idling it will eventually stop and go back to normal. Recently it seems to have gotten worse. Same thing happens when I start the car, Revs up and down. I start driving without touching the gas its moving faster than it should. And now when I am going slow it will chug as if I am hitting the gas pedal in little spurts. Sometimes it will stop. Someone did tell me its a air control valve issue. I have a CEL code 8 and 9 top dead center and the other code I forgot. Any help for us guys would be nice,

Stop thread jacking and fix your codes. Make your own thread if after fixing the codes, the problem persists.

 

[RonJ]

So when I bought my car the idle jumped from 1000rpm up to 1500rpm and kept repeating. I took my iacv off and cleaned it, I made sure it was super clean before I put it back in. It was fine for about 3 days and now it's doing it again. But if I tap the gas pedal, it stops, everytime. Also, when I start my car it's a rough start and idles around 2000rpm. Any ideas on what's going wrong? Anything would be helpful!

You need to supply much more basic car information if you would like intelligent replies. What car and ECU is attached to the B16a2? Is the engine bone stock or modified? If modified, list them. What CEL codes are thrown?

 

[Sparky94]

You need to supply much more basic car information if you would like intelligent replies. What car and ECU is attached to the B16a2? Is the engine bone stock or modified? If modified, list them. What CEL codes are thrown?

1997 civic hatch with 2000 b16a2 swap. Converted to obd1 with P30 ecu. Only mod is an short ram intake. No CEL codes are thrown

The cars also overheating. I have the fan jumpers out so it runs all the time because the sensors toast. It's not a normal rad, it's double the size. There's no white smoke coming out the muffler, I've added more coolant and got rid of any air bubbles that might be in the system and it's still overheating

 

[RonJ]

1997 civic hatch with 2000 b16a2 swap. Converted to obd1 with P30 ecu. Only mod is an short ram intake. No CEL codes are thrown

When the idle is high and surging, remove the air intake system and then use you finger to cover the hole leading to the IACV inside the throttle body. Does covering the hole dramatically drop the idle speed and stop the surging?

The cars also overheating. I have the fan jumpers out so it runs all the time because the sensors toast. It's not a normal rad, it's double the size. There's no white smoke coming out the muffler, I've added more coolant and got rid of any air bubbles that might be in the system and it's still overheating

Is the exhaust header touching the over-sized radiator? Have you replaced the thermostat?

Describe exactly how you bled the cooling system.

 

[Sparky94]

Is the exhaust header touching the over-sized radiator? Have you replaced the thermostat?



Describe exactly how you bled the cooling system.

Header isn't touching the rad, haven't replaced the thermo but I have a new one.

I let the car idle for 20 minutes with the rad cap off. Drove around for 10 minutes with the rad cap on but cracked open. Got home topped up the antifreeze, tightened the cap, let it sit running for 5 minutes and it started to overheat.

I didn't check if the lower rad hose to see if it was hot or cold. My fans jumpered out at the thermostat does that matter?

 

[RonJ]

Solving the overheating issue is obviously #1 priority.

Do you have any solid reason to believe the ECT fan switch on the thermostat housing is bad? If not, UNjumper the fan switch and replace the thermostat (OEM = best). Next bleed the cooling exactly like this:

http://honda-tech.com/showpost.php?p=39830585&postcount=3

If the temp gauge needle rises to the halfway mark, stop the engine and let it cool, and then try again. If this^ solves the overheating, then do the test of the high/surging idle that I mentioned.

 

[Sparky94]

Yeah when fan switch is plugged in properly the fan won't come on. But jumpered out its fine. I'm going to replace the sensor.

I've got the oem thermostat. I'll be fixing this tomorrow. I'll let you know how it goes. Thanks for your help!

 

[Sparky94]

Okay so now my car won't start. I drained the coolant, took my intake out for better access. Disconnected the battery. Removed the ground from the thermostat housing. Put the thermostat and housing back on. Attached the ground to the housing. Unplugged the tps sensor and the sensor ontop of the fuel rail (not sure what it is) just to reroute the tangled mess of wires. Filled up the rad, connected the battery, then started the car. After several cranks it started, idled for about 30 seconds and died. And now it just cranks over

And I plugged all sensors back in before I connected the battery

Solving the overheating issue is obviously #1 priority.



Do you have any solid reason to believe the ECT fan switch on the thermostat housing is bad? If not, UNjumper the fan switch and replace the thermostat (OEM = best). Next bleed the cooling exactly like this:



http://honda-tech.com/showpost.php?p=39830585&postcount=3



If the temp gauge needle rises to the halfway mark, stop the engine and let it cool, and then try again. If this^ solves the overheating, then do the test of the high/surging idle that I mentioned.

Okay so my overheating seems to be fixed. I didn't replace the ect fan switch today, didn't have the proper sized wrench with me. But I got thermostat in, and the coolant flush done, but my thermostat isn't opening (the lower rad hose isn't getting hot)

I'm not running coolant yet, I just did water for now as I forgot to buy antifreeze. I let the car idle for 30 minutes with the fan constantly on, and then 45 minutes with the fan constantly off. The temperature didn't change one bit. I drove home (about a 20 minute drive) with the fan constantly off and still no change in the temp. Any thoughts?

I got my car running, just a bad ground