Weird idle issues

Chris S

Member
Joined
Feb 17, 2016
Posts
22
Reaction score
0
Location
Austin Texas
Try watching Scotty Kilmer's YouTube video "How to fix a car that idles poorly" basically clean the throttle body.
 

Jpocolypse

Well-Known Member
Joined
Apr 16, 2015
Posts
134
Reaction score
0
Location
North West Ohio
I never thought about the intake manifold gasket. I'll look into that after I am certain it's not IACV related. And I've thoroughly cleaned the throttle body already so I'm pretty sure that isn't the issue. If getting a new IACV gasket doesn't solve the problem then I'll pick up a few extra throttle body and IACV gaskets and start switching parts between my two cars until I figure out which part is causing the problem.
 
Last edited:

Chris S

Member
Joined
Feb 17, 2016
Posts
22
Reaction score
0
Location
Austin Texas
Could be the fuel injectors. Take a listen while it is running with a long screw driver pressed up against the base of each injector and the round handle end in your ear. You can hear whether or not the fuel injector is clicking and if it is clicking regularly. Might also be the distributor. You could swap distributors...
 

Jpocolypse

Well-Known Member
Joined
Apr 16, 2015
Posts
134
Reaction score
0
Location
North West Ohio
Hmm that's a new one I'll have to try that once I eliminate the possibility of a bad IACV or throttle body. I replaced the gasket on the IACV today, but it still has a vacuum leak. I'm thinking its probably the throttle body gasket that's leaking now because I've had it apart at least half a dozen times and its not sitting very flat anymore.
 

Jpocolypse

Well-Known Member
Joined
Apr 16, 2015
Posts
134
Reaction score
0
Location
North West Ohio
I swapped both the IACV and the throttle body with the old car and it solved the vacuum leak, but now I'm back where I started. It still idles rough when its idling around 750 RPM. I was watching the fuel trims as I took it for a drive and I noticed its running rich when idling and runs lean when accelerating but not WOT. Its like it goes from too much fuel to not enough fuel as I push the gas pedal.
 

Jpocolypse

Well-Known Member
Joined
Apr 16, 2015
Posts
134
Reaction score
0
Location
North West Ohio
What I don't understand is how a vacuum leak can cause it to run rich at idle. A vacuum leak would cause extra air to get in which would lean it out wouldn't it?
 

agginline86

Well-Known Member
Joined
Sep 13, 2012
Posts
822
Reaction score
1
Location
SoCal
would a primary O2 sensor that is going bad, but not bad enough to throw a code could cause this?

wouldn't be the first thing I check, but seems like you've covered almost everything already. I had similar symptoms when mine went bad
 

Jpocolypse

Well-Known Member
Joined
Apr 16, 2015
Posts
134
Reaction score
0
Location
North West Ohio
I checked the O2 sensor readings using my phone connected to the car's OBDII port and at idle it will hang out at 0.04 volts for a while then jump up to 0.8 volts for a while then back to 0.04 volts. does this sound normal? At some point I want to swap the front O2 sensors between my accords and see if that makes a difference. Also does anyone know where the long coolant line that connects to the IACV goes because I need to replace it on my old sedan. The only way I was able to get the IACV off was to cut the hose. Also how long is it and what size is it?
 

spacemonkee23

Well-Known Member
Joined
Aug 26, 2014
Posts
351
Reaction score
3
Location
Placentia, CA
Have you checked the Fuel Pressure Regualtor yet? Check its vacuum line for fuel and put on a vacuum hand pump to see if it holds vac.
 
Back
Top