JustBeatIt

I've got a '99 civic dx hatch with 180k on it. It's got a 1.3 liter D13B4 motor. Just about a week ago it started doing the idle surge that I've heard is quite common. I read up on the common causes (FITV and IACV and air in the cooling system) and tried to remedy each. My motor doesn't have a separate IACV like on many other honda motors. Instead it's just got a simple bypass valve with the idle adjustment screw on it. I took the throttle body off and thoroughly cleaned the whole thing. I put it back on and the problem persisted. I took it off again and this time dissassembled the FITV and cleaned it again. I even took the magnet that actuates the valve off and checked/cleaned it. The problem persisted. I then bled the cooling system as per the manual. Problem still persisting. What do I do next? What else could it be?

delsolproblems

Test the MAP sensor signal voltage and/or check for vacuum leaks.

JustBeatIt

I checked for vacuum leaks by spraying carb cleaner all around the intake manifold and looking for damaged vacuum lines. Couldn't find anything.

How do I test the MAP sensor?

JustBeatIt

I've pulled that damn throttle body off the motor about five times now and checked everything out. It's clean and I've take everything off it and put it back together. I've had the IACV apart and it all looks fine.

Now when I run the engine it will surge even when the throttle is opened, not just on idle.

I checked for codes and the only one I got was for the Idle Air Control System.

WTF!!!!?????

delsolproblems

To test the MAP sensor voltage, completely warm the car up to normal operating temp. Set a meter to 20v and wedge the black probe in the battery negative post. Stab the red probe of the meter into the MAP sensor signal wire (i think it's red/something) while the car is idling. If the MAP sensor is working correctly, the voltage reading on the meter will reflect the amount of vacuum you are making in the intake manifold. Lower voltage means more vacuum. Post the voltage and the exact RPM the car was at. You should also test your spark at all four wires. To test the spark, either buy a spark tester or:

Disable the fuel injectors and get a new or known good spark plug. Set the gap of this plug to your vehicle's specifications and make sure it is clean afterward. Wear gloves (welding gloves work great), preferably with latex or nitrile gloves underneath, and remove a spark plug wire from its plug. Connect the good plug to the end of the wire and hold the plastic deep-well tube at the very tip of the wire end with the threads of the plug touching bare metal on the valve cover. Have an assistant crank the motor while you watch the spark, carefully keeping all body parts away from the plug, motor and car body. Different types of plugs have different colored sparks but usually a good spark is a thick, strong flow of bright pink or is at least bright. Little blue or pink "lightning bolts" indicate a weak ignition. Check all four wires. If the sparks at all of the wires are weak, try holding the threads of the plug against the battery negative post to see if the better ground makes a stronger spark. This will test your entire ignition.

You follow a similar procedure when using a spark tester. Is this manual or auto?

JustBeatIt

It's an auto.

JustBeatIt

I think I've solved the problem. I swapped on a new Denso magnet/sensor thingy that goes on the end of the IACV and it's been working great. I borrowed it from a buddy so now i've got to locate one of my own so I can return his parts. Anyone know where I can find one of these? See pics below.

ThatRHDstatus

have u checked this out

https://honda-tech.com/forums/showth...light=fix+fitv

JustBeatIt

Yeah, I have. I've done everything to clean it out. I just need to replace that faulty part now.