another bad idle thread..

[hondacord93]

i know your all sick of reading aboout people with bad idle problems but ive tried almost everything and i had a few questions.. my idle is normal (around 700 warm, 1200-1500 cold) but cold or warm my engine will bog or missfire, im not sure how to describe it.. i throw no CEL but when i check it i get a 14 which i beleive is my IACV. ive cleaned my IACV, FITV(tighted as well), EGR, checked for bad vaccum lines, bled coolant, my spark plugs look good but i have some new NGK ones on the way. wires look good, i cleaned the buildup on the dizzy cap. the bog happenes in any rpms but is most noticeable between 1000 and 2000 rpms. i suspect my O2 but i thought it doesnt turn on when the engine is cold and when i unplug it, it will still happen. when i unplug my IACV my engine will not rev over 3000 or so and it will just loop between 1000 and 2500. i noticed that my exhaust smells very rich which also makes me think its my O2.. my MPG seems to be below par as well. the car runs fine with no hessitation and the bog is not noticeable durring normal driving. i know my EGR ports are due for a cleaning but im putting it off because i dont have a slide hammer and i just dont want to do it.. could it be my timing? i may have missed something but im running out of ideas and i dont want to just start replacing parts.. any help or suggestions would be greatly appreciated.

[93-accord-505]

try buying a brand new IACV. i think they run around 50 bucks

[DarkHusk11]

At a junk yard if that, last time i went to auto zone to price it it was over 200

[hondacord93]

yeah ebay hes em for around 40-50 used, but would a bad IAC cause the engine to run rich?

[deevergote]

Running rich is very often due to the o2 sensor. That's the only sensor that provides any input after the combustion event occurs, therefore it is the one responsible for sending the signal to the ECU to adjust the mixture. The o2 feedback only comes into play when the engine is at operating temperature, though.

What brand o2 sensor do you have? And how old is it? When you replace it, be sure to use NTK/NGK or Denso ONLY (rockauto.com has a good price on Denso.)
I get a bog at times, and I'm quite sure it's an o2 issue. When my car is back up and running, I'll change it to be certain. However, I have a modified ECU, and the chip I'm currently running has disabled the o2 sensor... and i get no bog.
When running the map with the active o2 sensor, my CEL only comes on around 50mph, and then it gives me code 43.

Have you attempted to set your base ignition timing and idle according to the threads written by Hondafan81? They are the most thorough and accurate. Follow those to the letter, and you can be sure you've done it right. Replacing those parts may be necessary, though.



You may want to try another ECU as well. Meet up with another CB7 owner and do a quick swap... it's easy and harmless to do.

[hondacord93]

Running rich is very often due to the o2 sensor. That's the only sensor that provides any input after the combustion event occurs, therefore it is the one responsible for sending the signal to the ECU to adjust the mixture. The o2 feedback only comes into play when the engine is at operating temperature, though.

What brand o2 sensor do you have? And how old is it? When you replace it, be sure to use NTK/NGK or Denso ONLY (rockauto.com has a good price on Denso.)
I get a bog at times, and I'm quite sure it's an o2 issue. When my car is back up and running, I'll change it to be certain. However, I have a modified ECU, and the chip I'm currently running has disabled the o2 sensor... and i get no bog.
When running the map with the active o2 sensor, my CEL only comes on around 50mph, and then it gives me code 43.

Have you attempted to set your base ignition timing and idle according to the threads written by Hondafan81? They are the most thorough and accurate. Follow those to the letter, and you can be sure you've done it right. Replacing those parts may be necessary, though.



You may want to try another ECU as well. Meet up with another CB7 owner and do a quick swap... it's easy and harmless to do.

thanks for the input. i am unsure of the brand of O2 sensor but its probably due for a change. i found a denso O2 that i want to buy but it just seems weird that nothing changes at all when i unplug it. i have set my base idle, but have not attempted to adjust my timing. it seems like a fuel delivery issue but the fact that it does it cold or warm confuses me... i should just fork out $45 for a new o2 since i think it was a generic one that i had to re-wire to fit my OEM plug. but if it bogs on cold start wouldnt it mean its something else?? also my car will almost completeley lose power driving up certain hills (similar to problems i had durring normal driving before i replaced my last O2) untill i floor it or keep it in second gear in higher RPM's. would a bad oxygen sensor cause this?

[deevergote]

Cold startup is probably not the o2 sensor... However, if you don't know the age or brand of the sensor, start there. Replace it. Doing so won't hurt, and may help. If anything, it's at least good preventative maintenance.
Also, make sure ALL ignition components are new (cap, rotor, plugs, wires... make sure the plugs are not covered in oil.)

The bogging during acceleration is what I experienced before I deactivated the o2 sensor (not something you're capable of... don't worry about it.) The sensor is likely the cause of that, but not 100%.


If you had to re-wire, I REALLY hope you modified the sensor wiring, and not the car's wiring. Modifying the wiring can alter the resistance, and cause incorrect readings.

[hondacord93]

Cold startup is probably not the o2 sensor... However, if you don't know the age or brand of the sensor, start there. Replace it. Doing so won't hurt, and may help. If anything, it's at least good preventative maintenance.
Also, make sure ALL ignition components are new (cap, rotor, plugs, wires... make sure the plugs are not covered in oil.)

The bogging during acceleration is what I experienced before I deactivated the o2 sensor (not something you're capable of... don't worry about it.) The sensor is likely the cause of that, but not 100%.


If you had to re-wire, I REALLY hope you modified the sensor wiring, and not the car's wiring. Modifying the wiring can alter the resistance, and cause incorrect readings.

yeah time for a new o2.. i only had to rewire the plug from the old sensor, nothing on the car. i have smooth acceleration with my new TPS, but only on certain hills will my car lose power and sometimes backfire. it seemed like my idle was better while my AC was on, but it may have been just not noticeable because of the extra load on the engine. i was thinking about maybe changing my ignition coil?