diverdwn

Hello all,
I have a 2005 Civic EX. 1.7, engine, automatic transmission.
My brother and I replaced the head gasket over the last weekend. He is a retired Mechanic and I was pretty much the helper. The replacement went okay and the we put it all back together.

When we were done the car started just fine but after two minutes at idol the engine started surging between 1k and 2k, over and over again. My brother had gone home by this point.

I pulled the codes, P0507, P2279, P0134. My Google search led me in several directions and lots of web pages and although the symptoms have decreased and I can drive the car, it's still wonky..

The Civic had no Idol issues before the head gasket replacement.

What I did
Checked for vacuum leaks with carb cleaner, didn't find any
Pulled the ECU fuse to reset the codes, run for 10 mins.. codes came back
Checked and bled the coolant to ensure no bubbles.
Removed the TB and cleaned it and the IAC with carb cleaner.

After cleaning the IAC and replacing the TB, the engine idols fine at 1k. This last until you put it into gear then it jumps to 2k and idols there. I had no reason to put my foot on the gas with an idol at 2k. I did notice that while moving the car would surge, from 1k to 2k.. When I come to a complete stop it goes back down to 1k and sometimes down to 500 rpm.

I'm thinking I need to recheck for vacuum leaks, any suggestions as to what specific items? If that isn't the issue, check the timing. I was hoping that you guys could throw some Ideas my way. I'm not looking forward to pulling all that stuff back of to check the timing.

Any assistance in this would be awesome!

Thanks!!

mikey1

an intake leak somewhere,

vaccuum leak/hose
intake gasket/head leak
throttle body

etc etc....it is sucking air from somewhere it shouldnt be

nsrhonda89

Check your brake booster and pcv valve vacuum lines.