ok i replaced the iac three times and the cel comes on still (code 14), i know the iac's work so what could be the prob? And changing the iac's i also changed the fast idle valves three times, also made sure the plastic screw was all the way in. but no change. After the car warms up it stops but when you start to drive it the idle surges alittle. And the car has no power from 1000 to 3000 kinda bogs out, and you can hear the iac sucking in air real loud. Even when i unplug the iac sensor it still sucks up air. Could it be eletrical, does anyone have a ecu layout for a 93 dx po6 ecu, so i can jump the wires stright to the ecu to see if that will work. Any suggestions PLEASE HELP.


Modified by 716pro at 8:49 PM 6/2/2005

 

make sure u have the right plug in the iacv. it happened to me

 

did that, made sure even changed a couple of plugs around, but no change. Even changed the comp. but no change. wtf

 

 

HELPPPPPPPPPPPPPPPPP

 

Check the vacume line, its on the intake manafold on ya YOUR right hand side toward the back. if thats not connected ya idle will go up and down like someone is tapping on the gas.

 

Is this a stock 93 Dx? Any mods? Recent maintenance? Did this problem just start out of no where? How high does the idle surge? If the engine is hot (which means the FITV should be closed down) and you unplug the IACV, what happens to the idle - what does it settle down to? When you unplug the IACV, no air should be pulled through it (since it's a 2-wire variety) - so that could be a problem.

 

its a stock 93 dx motor, no mods at all. the idle surges until its warmed up just like your normal iac problem does , but when its warmed up it idles fine until you drive it and it has no power between 1000 and 3000 rpm. Also after it has been idleing after its warm it will start to surge and make a wierd pop noise coming from the intake, and you can hear the iac sucking in air real loud. This happens for a second then stops then it will happen again. If i try to drive it when its doing this it bogs, like its getting to much or to little air, and when i hit the gas you can actually hear the iac suck in air real real loud.

 

What happens to the idle if you unplug the IACV? What does it settle down to?

 

well it dosent settle to 500 like it should the lowest i can get it to idle with it unplugged is 1000, and thats with the screw turned all the way down for the idle. Now what.

 

 

huh

 

You have a vacuum leak - find it and fix it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">You have a vacuum leak - find it and fix it.</TD></TR></TABLE>

Yep... that's what it sounds like to me too. Sounds like a big leak from what you're describing. Also check your valve timing/ignition timing and do a compression test. If your losing a seal around one or more of your intake valves, it will do this too.

 

ok i checked like 5 times to see if t here is a vacum leak there isnt.Ialso did a comp. test cylinders are fine. The timing is dead on , now what about the CEL for the IAC?

 

get carb cleaner and run ur car and spray all ur lines and gaskets. if the idle gets different theres ur leak. good luck

 

i kinda had the same problem...i couldnt figure it out, i bled the coolant system, and she idles fine now....doubt its your problem, but maybe check it out... maybe it was just a coincident that when i bled my coolant, the car wanted to run right

 

The only way for air to enter the manifold is through the Idle Air Bypass screw, the IACV or the FITV if equipped. The sum of the air from those sources is suppose to idle the engine at ~750-800 rpm. Now, if you say that the idle screw is all the way in and the IACV is unplugged, then where is the engine getting the additional air to make the engine idle up?

You have a vacuum leak, whether it be a tight throttle cable, bad gasket or hose - its somewhere.

 

i am pretty sure i dont have a vac leak because i used almost a whole can of starting fluid on the car, and the car never jumped idle. I know how to bleed the coolant but what exactly did you do to get the air out of yours? maybe it will help if i do it the way you did yours. And the throttle cable isnt 2 tight, but i will check anyway.

 

take off ur rad. cap and run the car for a while. if it goes down put some more in or on the back of the therm. housing by the dizzy theres a bleeder valve which is a 12mm wrench. make sure the car is warmed up though

 

Start with a cold engine. Turn the heater controls to full hot. Take the radiator cap off and top off radiator. Start car and allow to idle till thermostat opens/radiator fan kicks in. Top off radiator as neeed. Replace radiator cap.

My engine did not have a bleeder screw in the thermostat housing as some older engines do.

 

My 92 LX was doing pretty much the same thing, I tried everything. Mine ended up being a bad O2 sensor, didn't throw a code or anything, but that's what it was.

Good luck

d

 

well now its throwing the code 10( IAT) and the IAC (code 14), but i was messing around and changed a few wires around from the IAT and the IAC and the only code i got was for the IAT. Switched them back and now i get both. I know the wires are in the right place because there is another civic in my yard and i looked at those and compared them. The car isnt making the wierd suck noise anymore now its idleing at around 800 or 900 and dropping down to around 500. Keeps going up and down for a minute then stops, then will idle fine until i hit the gas and let the motor idle again it will do it for 20 seconds or so. Keeps repeating. I am gonna let the car cool down and see if it idles fucked up when its cold, this is getting retarded.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 716pro &raquo;</TD></TR><TR><TD CLASS="quote">The car isnt making the wierd suck noise anymore now its idleing at around 800 or 900 and dropping down to around 500. Keeps going up and down for a minute then stops, then will idle fine until i hit the gas and let the motor idle again it will do it for 20 seconds or so. Keeps repeating. I am gonna let the car cool down and see if it idles fucked up when its cold, this is getting retarded.</TD></TR></TABLE>

Not to alarm you, but that is exactly what my car did when I had a vacuum leak. Now I have a question for you... does your car have cruise? Does your intake manifold come from a car that had cruise? I left that hose unplugged (cruise control vacuum supply) on the rear driver's side of the intake manifold. There is a nipple on the IM for the cruise supply... make sure you didn't forget to plug it in or block it off. It's easy to forget that one because it's out of sight.

For the cooling system (I've done this 20 times at least in the last few weeks before I put the new headgasket in last weekend) from cold remove the rad cap, top it up, start the car, turn the heater control to maximum heat, but leave the fan off. To avoid spilling coolant all over your rad and stuff, stick the overflow hose at a downward angle lower than the rad cap where it can just leak overflow onto the ground... gravity will take care of the rest. As coolant gets hotter, the air bubbles will rise and you might have to keep topping up the coolant level. Do this until the cooling fan comes on... then top it up (cause the level will go down when the fan kicks on) until the fan turns off, then quickly put the rad cap back on.

 

So i went out today to start my car up and it idles fine, no up and down idle just a smooth idle. The car is still throwing the # 10 and 14 codes though. I reset the comp twice so i dont know what the hell is going on. The car still feels like it bogs a little until around three grand. You can sort of hearit bog like its getting a little to much air and not enough fuel. So now does anyone have any suggestions?