Civic EG

I have a 93 honda civic ex. It has a crazy surge after it warms up or i give it a rev. But it clears up when i drive it. i sitt at stop sign and it starts surging again. im lost on this. its not throwing an CEL

Try cleaning the IAC Valve (on back of intake manifold) and bleeding any air out of your coolant system.

any diy on bleeding the rad fluid? havent done it befor.

-Take the radiator cap off when the engine is cool.
-Start the engine.
-If your engine has one, crack open the coolant bleeder screw. It will be where the upper radiator hose meets the head if it's even there (my '94 'Teg had one, but my '97 'Teg doesn't...*shrug*).
-Let it warm up at idle.
-Fill the radiator as needed.
-Squeeze the upper radiator hose as you feel necessary.
-Check the lower radiator hose every once in a while to see if it's getting warm. When it is hot, the thermostat has opened.

If that's not the problem and you've cleaned the IACV, you could have a vacuum leak somewhere. Spray carb cleaner all over every mating surface where a gasket is, every vacuum hose.

That One Dude wrote:-Take the radiator cap off when the engine is cool.
-Start the engine.
-If your engine has one, crack open the coolant bleeder screw. It will be where the upper radiator hose meets the head if it's even there (my '94 'Teg had one, but my '97 'Teg doesn't...*shrug*).
-Let it warm up at idle.
-Fill the radiator as needed.
-Squeeze the upper radiator hose as you feel necessary.
-Check the lower radiator hose every once in a while to see if it's getting warm. When it is hot, the thermostat has opened.

If that's not the problem and you've cleaned the IACV, you could have a vacuum leak somewhere. Spray carb cleaner all over every mating surface where a gasket is, every vacuum hose.

Im leaning more toward the rad needing a bleed since i just changed a line

you may need to have someone give very light throttle to get the thermostat to open. But once it does, just keep topping off the radiator w/ coolant as the bubbles move through the system and come to the top of the radiator.

teal_dx wrote:you may need to have someone give very light throttle to get the thermostat to open. But once it does, just keep topping off the radiator w/ coolant as the bubbles move through the system and come to the top of the radiator.

Or just open the throttle your self ... you'll be standing near the throttle body anyway.

You might also check your FITV.

wheres the fitv located?

Wicked Customs wrote:wheres the fitv located?

on the bottom of the throttle body.

The FITV is located on the bottom of the throttle body. 99% of the time it's the cause of idle surge in a D series.

To fix it:

1. Personally I like to remove the entire throttle body first so it's easier to get at the FITV.

2. Remove the FITV (the highlighted section). There should be 3 bolts holding it to the throttle body.



3. Remove the plate at the end of the FITV. This is going to reveal the plastic piece that comes loose.



4. You'll see a white plastic piece on the inside. Unscrew it by rotating it counter clockwise until it comes out. It does come apart so make sure it doesn't come apart and fall all over the place. It should look like this:



5. Clean all the pieces to the FITV and reinstall it within the housing. Flip the FITV over to see the side that connects to the throttle body. There should be 3 holes (other than the bolt holes). Looking at the one highlighted in the image, you should tighten your plastic portion on the inside of your FITV until it is flush with the inside of that hole - the same way it is shown in this picture:



6. Bolt your FITV back to your throttle body, and your throttle body back to your intake manifold; making sure you connect all the coolant hoses and such. That should solve your idle surge problem.

PM me or let me know at least if this is helpful

ill flush the system then ill clean the IACV then that lol thats a big job.

rad flush has been done. and it still does it.

Edit: when i sqeezed the top and bottom rad line it felt like nothing was in the line. when i put fluid in it barely/ didnt even move

Butterzz wrote:The FITV is located on the bottom of the throttle body. 99% of the time it's the cause of idle surge in a D series.

To fix it:

1. Personally I like to remove the entire throttle body first so it's easier to get at the FITV.

2. Remove the FITV (the highlighted section). There should be 3 bolts holding it to the throttle body.



3. Remove the plate at the end of the FITV. This is going to reveal the plastic piece that comes loose.



4. You'll see a white plastic piece on the inside. Unscrew it by rotating it counter clockwise until it comes out. It does come apart so make sure it doesn't come apart and fall all over the place. It should look like this:



5. Clean all the pieces to the FITV and reinstall it within the housing. Flip the FITV over to see the side that connects to the throttle body. There should be 3 holes (other than the bolt holes). Looking at the one highlighted in the image, you should tighten your plastic portion on the inside of your FITV until it is flush with the inside of that hole - the same way it is shown in this picture:



6. Bolt your FITV back to your throttle body, and your throttle body back to your intake manifold; making sure you connect all the coolant hoses and such. That should solve your idle surge problem.

PM me or let me know at least if this is helpful

Thank you! I think I have to do this to mine. Very helpful....

I normally would try not to bump older threads, but this is majorly useful information for anyone with a d15. I spent hours trying to fix my idle and this DIY massively improved it. I like how the Haynes manual says nothing about that valve, too. Thanks!

i fixed my idle problem with the fitv. all it really needs is to be screwed back in they tend to back out over time with vibrations. cleaning it is good if u already that deep into it you might as well.. just be careful of the 2 8mm screws that hold the back plate on. both of mine snapped off in the fitv so i had to drill and tap it out to put new bolts in.