1998 Honda civic ex coupe 1.6L d16y8 sohc

The idle roams, when ac is on it steadies but high.
Sometimes while driving or accelerating it surges.
Seems to only happen when warm. But even high idle when cold.

Things I've done...
Cleaned iacv
Fuel filter
New radiator and a few hoses (made sure it was bleed)
Everything from my mechanic friend and the Internet refers
It being the iacv, so...
I changed it with one from amazon(did not work) so returned
One from auozone(doesn't work)

The only thing that seems to help but temporarily is a fuel system cleaner
Called bg44k I think.

Please help!

 

when do you mean by ROAMS

 

Between 1000 to 2300 rpms but sometimes it bounces between 1400 and 1800. While driving when I left off the accelerator to stop or turn it will bounce but not as fast a bounce. I have put 2 different iacv"s and no change?

 

Look for vaccum leaks
Adjust your tps sensor .5 volts at closed throttle 4.5 at wide open throttle.

Any check engine codes?

 

What is tps?

O2 sensor code
Small crack in exhaust manifold
Torque converter sensor

All these codes I've had well before this issue.

 

My mechanic friend put it on his Matco diagnostic and we also checked for vaccum leaks with brake fluid and he said no leaks and it has to be the IACV. I appreciate the help btw!

 

Throttle position sensor(tps)


My old 1996 gsr did this when my o2 sensor was faulty.

 

I'll try that on the tps, and possibly change the 2nd o2 sensor. I have already replaced the front one right after I got the codes 8 months ago.

I'll let you know how it goes tomorrow and again thanks for your time and help!

 

Don't even bother replacing the oxygen sensor until you get the crack in the manifold welded or replaced. It's just gonna foul like it probably already has.

Regarding the high idle, sounds like you have a vacuum leak you need to find.

 

How do you adjust the tps? It looks just like a sensor? Should I replace it.
How are the parts brand delco from autozone? I hear Hondas don't like aftermarket?

 

losin the screws(but dont remove them) get a volt meter and move the tps back and forth to adjust the volts. .5 at closed 4.5 at open then re tighten screws without moving the tps and your done.