Thread: Very rough Idle while in gear A/T

Ok update guys, valves, lifters, and cam seem to be in working order. Zero compression on 1 and 2 around 115 on 3 and 4. Put air to #1 and shot back out #2, so I'm going with a blown head gasket at this point and chalking the knocking sound up to detonation. What do you guys think?

Just wanted to post that I finally got around to replacing the hg which had a blowout between 1 and 2. Machined head, head valves checked, new water pump, timing belts etc. After I got it all put back together it still had a stutter at idle, bought a vacuum gauge and what do you know its only pulling around 10 inches at idle. Rev the motor vacuum shoots up to around 20 and smooth. So after much head scratching I found that I r dumb and had the two little vacuum lines that come off the top of the TB crossed and this was causing the (what I was told to be) vacuum regulator on the fire wall to I guess pull against itself? I don't know but what I do know is that after swapping those two that it is idling smoother than ever! Quick question though, how do you adjust the air idle screw properly? I have a data tap so I can get a good look at what everything is doing bit not sure on proper procedure. Thanks again guys for all the help.

the three nipples on top of the tb ?they were crossed ?how ? lol my car idles poor in drive too lol

The two nipples weren't crossed the hoses that connect to them were. Lol. You may have another issue though if u haven't just pulled the head or intake etc and just have a poor idle. The iac can become dirty and cause a rough idle as can egr valve or other vacuum leaks. I would recommend investing in a vacuum gauge because they can be a great diagnostic tool for more than reading just vacuum.