Hey,
I had a blown head gasket in my 2005 Civic LX with D17 engine. I took it all apart, got the head machined, and changed the gasket. My buddy put it back together while i was gone and when I got back it didn't start. So I took it all apart again and checked the timing and it looked off a tooth or two on the harmonic balancer. Now I know I should have used the cam shaft pulley instead, but in any case, i retimed it with the cam shaft and lined up the marks and --- starts! but rough idle ! replaced the pcv valve - still have the rough idle [img alt=""]data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7[/img] tried spraying brake cleaner in little bursts near hoses and listened for changes in the idle, nothing. it starts and runs normal, then once it reaches normal operating temp the idle starts getting shaky, goes down below 500rpm. when I rev and release, it shudders and when i turn it off it shudders

here are the specs i've got most recently:

the absolute throttle position on my scan tool was showing 9% when throttle was closed and 92.5% fully open. I adjusted the tps as far as it could go and got it down to 2% closed (multimeter read 0.12V) and idle was about the same, plus a got a code for low TPS reading. then I readjusted so that the multimeter read 0.5V-4.5V (Honda spec) and the scan tool once again shows 9%-92.5%. could this be the cause of my rich idle? the ECU misinterpreting the TPS? or maybe my scan tool is the one misinterpreting? the short term fuel trim is reading around -15% at idle and gets lower when I give it gas, approaching 0%.

I put it all into ChatGPT and it says --- THE TIMING IS OFF A TOOTH!?!?! How can it be!?!?! I'm willing to go back in there but wondering if theres a way I can be more certain, or something else....Thanks for any help!

i've : checked valve spacing, cleaned throttle body and air intake control valve, checked all the spark plugs repeatedly, checked head bolt torque, replaced pcv valve.

 

Set the crank pulley to TDC. Check to see if the cam gear sprocket is aligned and set to TDC. If timing is off one tooth, it will run like crap.