Yes I know this has been posted on many-a-times, but...

After I bought this car, I found out later it has an irregular idle. It usually jumps between 1k and 2k. This only happens if I shift past VTEC, for some reason. Anyway, after I took off the short ram I found masking tape over the IACV. After taking the tape off I tried to start the car and just after starting (in neutral) it killed. I tried it again but gave it gas and it started. As soon as I let off the gas however, it killed. After having it run until it's warm however, it stays on but it idles at like 200 rpms and the car feels like it is going to die.

I've heard it is the IACV, so we swapped it out. But the new one sent the motor to a 3000 rpm idle. So that didn't work. :banghead:

I've now heard either I have to reset my ECU by unplugging the battery for like 1 minute and then having the car run for 15 - 30 mins to let the computer reset with the new sensor (IACV)

But also someone suspects it just may be the Throttle Positioning Sensor. If so, I would have to get that from a dealership or something because no auto stores carry them... for Honda's anyway. :confused:

We are going to try to put the newer IACV one tomorrow and borrow a friends TP sensor and see if the car works.

Any advice?

Thanks.

no advice but good luck that tps might do it. id try it with the 2nd iacv that u used first

I had that problem, I cleaned out the iac valve with some good old carb cleaner, it helped about half the problem then I bled my coolant, it had some air causing 1krpm to 2500k rpm, bled it and everything was fine. I also thought it was the tps, you can also test it with a meter at WOT it should be practically a 4.9999999volts when not at WOT closer to 0volts.

Yes I know this has been posted on many-a-times, but...

After I bought this car, I found out later it has an irregular idle. It usually jumps between 1k and 2k. This only happens if I shift past VTEC, for some reason. Anyway, after I took off the short ram I found masking tape over the IACV. After taking the tape off I tried to start the car and just after starting (in neutral) it killed. I tried it again but gave it gas and it started. As soon as I let off the gas however, it killed. After having it run until it's warm however, it stays on but it idles at like 200 rpms and the car feels like it is going to die.

I've heard it is the IACV, so we swapped it out. But the new one sent the motor to a 3000 rpm idle. So that didn't work. :banghead:

I've now heard either I have to reset my ECU by unplugging the battery for like 1 minute and then having the car run for 15 - 30 mins to let the computer reset with the new sensor (IACV)

But also someone suspects it just may be the Throttle Positioning Sensor. If so, I would have to get that from a dealership or something because no auto stores carry them... for Honda's anyway. :confused:

We are going to try to put the newer IACV one tomorrow and borrow a friends TP sensor and see if the car works.

Any advice?

Thanks.

check your sensors: maf, map, ect. an out of range signal from any of these sensors could all affect your engine rpm at idle. get some repair manual for your ride and read about the fuel and emission section. that should help you understand what these sensors are.

reset ecu first before spending money. you can disconnect neg terminal or just pull the fuse

reset ecu first before spending money. you can disconnect neg terminal or just pull the fuse

Leave positive terminal on but take off negative. Car off I'd assume.

And what fuse are you talking about specifically?



Thanks for your help guys.

has anyone thought to re-adjust the idle/mixture speed?

there should be an ecu back-up fuze in engine compartment fuse box marked ECU or BACK UP 7.5 amp or 10 amp

Ok, I put a new IACV on it. And when I started it... it now has an idle. But... it was jumping between 1800 and 2600 for a rev bounce at idle. So I let it run. Later I thought, "Oh yeah, didn't actually connect the sensor!" So I shut it off and plugged in the sensor. Now when I started it, an irregular idle was heard again but this time it jumps between 1400 and 2000 rpms.

I then shut off the car and pulled both the hazard fuse and the backup fuse... I waited about 30 seconds before putting each back in. I started it up but it still did it.

I then completely disconnected the battery and waited about 30 seconds and re-connected it. Started it and it still did it.

What do you guys think?

BLEED THE COOLANT, on the upper radiator hose there is a valve loosen it with the car running spurts of coolant should come out. Have a couple rags with you. Also dont open the valve all the way little by little you'll see what Im talking about. Once the air is all out the engine should come down to a nice idle.Don't forget to tigten the valve.
I also open the radiator cap for a brief moment to quicken the process, if you do it only do for a small time app 30 seconds. Good luck and get back to us.

the ecu needs more time than 30 secs. to reset .. leave the fuse or neg. batt terminal off for more time then reconnect start car and let idle it shouldn't jump... also check egr valve for sticking

the ecu needs more time than 30 secs. to reset .. leave the fuse or neg. batt terminal off for more time then reconnect start car and let idle it shouldn't jump... also check egr valve for sticking


This whole time, my CEL has been on. I failed to mention that. However, I ran the test and the only code it was throwing out was Code: 41... which is something with the O2 Sensor. Do you think that might affect something? Or no...

And sorry, what is the EGR valve? (full name) Kinda slow for some abrivs. :grinyes:

yes the oxygen (o2) sensor will/can cause that problem I had the same swapped o2 sensor reset ecu and it ran fine after that the egr valve is the Exhaust Gas Recirculation valve. it should be located right behind the distributor it looks kinda like a space ship