I have a 94 Del Sol, VTEC modle, 5 spd, Intake, DC header, and MSD Blaster coil.

This has been going on for months and its driving me insane.

OK here's the story.... I start the car, everything is fine. I get in the car, drive 10 feet, put it in nuetral and it begins to surge between 800 and 1500 RPM. This used to happen only when the car was warm. Now it surges when the car is cold and warmed up. So pretty much all the time. The IAC and FITV are both new.

Now when it starts to surge i take the intake tube off and put my finger over the upper port inside the TB (there is suction on it) and the surging instantly goes away. The upper port leads to the IAC valve..... What gives?

I've back probed every sensor under the hood. All of them are getting proper voltage and the voltage drops on the ground sides are right where they should be.

For a while (just to see if it made a difference) i was driving the car with the IAC valve port completely sealed off. (Duct Tape) The car didnt surge at all....untill it reached max operating temp

Then I put a small hole in the tape, just so the car would stay running when it was really cold out. I would do some local driving and everything would be fine. It started to surge again when the car reached it's max operating temp.

The port is no longer sealed off, and it surges all the time...exept when im at a cold start up. But as soon as i drive and put it in nuetral it beginns to surge. Even when it's still cold.

Sometimes the surging will just settle itself out, but most of the time it just keeps on surging. And then sometimes, it will be cold, and there will be no surging in nuetral, sometimes it just randomly starts to surge in nuetral, but when its warmed up it surges all the time and does not settle out.

I've done countless vacuum leak tests.... haven't found any.

Sorry for the long post, just trying to get as much information out as i can. This has been going on for months and it just sux sitting at a light and the engine just revs up and down up and down up and down.

Any ideas?

 

try this.

 

here's an idle trouble shooting guide
http://www.ef-honda.com/ben/Badidle.php

 

OK so i just tried bleeding my coolant and my car has no bleeder screw so i had to use the radiator cap..... holy shit there are a ton of air bubbles everywhere.

I must have sat out there watching this air bleed out for 45 minutes and still there was a ton of air bubbles comming out...should it take that long or longer? The car was surging while this was going on by the way. I'll keep on bleeding it. Keep hittin me with ideas tho.
thanx

 

search for FITV....this seriously gets covered every 15 seconds on HAN....

 

im on a laptop standing in front of my surging car watching air bleed out of the coolant...been about an hour now and still there are air bubbles in the system.
i removed the intake tube and i plugged the IAC valve port w/ my finger and the suging stops, i take my finger off and it comes right back!!!

Im so damn confuesed it shouldnt take this long to get the air out. im bout to jus take this p.o.s to the shop.....I cant deal with this shit any more

 

Check the seal around the brake booster...
My buddies CX that we swapped had a similiar idle surge problem...
The seal that goes around the brake booster (Circular thing in front of driver side firewall) was leaking...

Try running your finger around the seal, or spraying carb cleaner to see if the rpms change suddenly...

Good luck!