Rough idle once warm

dryeager

New Member
5+ Year Member
I started having this issue recently so I thought maybe I had a shot ring so I did a DRY compression test:
#1: 120
#2: 110
#3: 120
#4: 120

They are low but I am not burning oil nor does it smoke. No CELs either. Just a rough/missing type idle ONLY after the car is warm. Checked the plugs, they are all in good condition. OHMed out the wires and they are all within spec.

So any thoughts or clues?
 

RonJ

Banned
Car? Engine?

Cap and rotor?

CEL work?
 


itsmycookie

#1 a*****e
Registered VIP
Registered OG
5+ Year Member
10+ Year Member
plug in a diagnostic tool if u can.

it sounds like the Idle air control valve to me. u can clean it out just to make sure that isnt it though.
 

dryeager

New Member
5+ Year Member
1998 Honda Civic - D16Y7

Cap and rotor - inspected and fine.

No Cels. I was going to take a look at that this weekend. I will report back with images hopefully.
 


RonJ

Banned
Does the CEL work or are you saying you checked for codes with a code reader?

Describe what you mean by rough idle. Fluctuating high and low? Just low? High and unsteady?

Did you do any work on the engine recently?
 

dryeager

New Member
5+ Year Member
Took the TB off. The IAVC had a little carbon in it but nothing major. Cleaned it and the TB up and put them back on. I have yet to drive the car so I am not sure if that was the issue but judging from it not being clogged or plugged, I am betting that wasnt it.

I didnt plug a code reader into the car since when I reset the ECU to do the compression test, the codes were erased. I am about to run up to Autozone so I will have them do that and report back.

Only work I've done on the car recently was I replaced the valve cover gasket as I thought it was leaking but it ended up being cam holder #5 being broken on the tab that the dizzy connects to.

The idle is rough but it really feels to me that it is missing. Meaning 3 out of 4 cylinders fired turning a revolution but it isnt consistent or steady - random.

Thank you again for all of your help! I hope we can solve this.
 

dryeager

New Member
5+ Year Member
*Update*

After cleaning the IACV the idle is a little higher and doesn't miss as much while its idling while warm. Again, its only missing while warm. I am starting to think this has to be electrical but I just cant narrow down what to check next. One thing that has changed is the miss is random at idle and also under 2500 rpm. Boggled.

I still havent had the codes read but I will as soon as I get a little extra time.
 

dryeager

New Member
5+ Year Member
Replaced cap and rotor thanks to O`Reilly's lifetime warranty on those two parts. Same issue.
 

dryeager

New Member
5+ Year Member
Update!!

I found a brand new set of OEM Honda wires in the basement and threw them on the my car. Low and behold, miss is gone! I still can not believe it. Will report back if I find anything else!
 
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