1981 Camaro Z28

[MP81]

O2 bungs TIG-welded in. Just need to have them coated. Still deciding if I want shiny or black. Don't really mind if they get dull, I suppose.

[bri2203]

Your car has two O2 sensors?

I would guess it only had one from the factory. Are you using one for a A/F gauge?

[MP81]

Yes, only one on the driver side. Other one will be plugged for now, and then yeah, later for a wideband.

[MP81]

Headers are back from coating. QC did an awesome job like they've done in the past.

[DynoDave]

Those look great.

[MP81]

Those look great.

Thanks! QC really did a great job.

As TSTONE mentioned, they will dull over time (my Cobalt's are a nice solid gray), but that may actually more fit the look of the rest of the car. But at least I have the before pictures I can always stare at.

[MP81]

Started the car yesterday since it had been about a month, let it run for about 20 minutes, as that is how long it took to come down to a still-high 1k idle (not even the ~700 rpm idle I've seen before when it would finally behave). Something I noticed is that when I'd rev it (in the past, a good solid rev would bring the RPM down to 700 when it would be trying to accelerate itself past 2500 rpm), the revs too a rather long time to drop back down - as if something isn't letting it operate freely. I feel like this has to be connected with its unwillingness to idle at a properly low speed.

JoeliusZ28 suggested rebuilding the carb, which I'm thinking is probably not a bad idea (given I'm sure it's never been rebuilt ever), but I was wondering if maybe there's a more simple solution. Throttle return springs, linkage, etc? I have yet to pull the air cleaner, maybe something is just sticking after the winter?

[Atrus]

I'd suspect anything connected to the throttle - the cable, springs, linkage....choke?

[MP81]

Could very well be. It'll start at high idle, as one would expect of a cold start. After a while, as you can tell the choke is opening, it begins dropping, but at a point, it stops dropping and stays there and then goes up shortly after. It's really quite odd. I've tried pulling up on the pedal with my foot, but that hasn't done anything.

I just don't want to adjust where idle is, in the possibility that it decides to idle where it's supposed to, which now would be too low. I think I just need to fire it up without the air cleaner on and have a look at everything.

[TORN]

Headers look great, do you mind if I ask what QC charged to coat them?

[MP81]

Headers look great, do you mind if I ask what QC charged to coat them?

No problem at all: they charge $240 for SBC headers. Real good group of guys there.

[MP81]

Put it on scales today. Actually a bit lighter than I was expecting. And I would've expected more weight up front than the 57/43 split it has.

[MP81]

Played with the carb over the weekend. Pulled the air cleaner assembly off and made sure none of the linkages were getting bound up or stuck, everything seemed to move pretty fluidly. Started the car up, and it came down to a 750 rpm idle (eventually moving up to 1k, but staying there) pretty quickly. Any revs dropped back down fast, as it should, and it never tried to spike up high like it did before. Pushing back on the high-idle linkage produced behavior exactly like what it did before. Same rate of climb in RPMs, etc.

So I have to believe the high idle linkage is/was sticking - WD40 should be good to free that up, correct? Or is there something better to use?

[TORN]

Use a 3 in 1 oil or liquid wrench. WD-40 will dry up and not be of much help.

[MP81]

Good to know - similar to how WD-40 should not be used on door hinges, since it'll dry out after collecting a bunch of dirt, exacerbating the original problem.

Would it be a good idea to apply the oil to the rest of the linkages/springs up there at the carb as well?