Bill's EFI Drama AKA A Game of Name that Component!

[Zed Head]

There's some good AAR stuff in here - 

 

[mentalite]

Yay!  Finally got on top of the BCDD issue by following the advice to adjust it.  It took a while because it way WAY out of adjustment and I was patiently making a quarter turn at a time, then driving it.  Rinse.  Repeat.  I was to the point of believing I had adjusted so far that it just had to be broken, then Blammo!  I hit the sweet spot.

It feels good to make progress no matter how slight.  So I now have all connectors polished up.  All vacuum lines inspected, PO fuel pump bypass corrected, lash pad replaced, and a band-aid on the AFM issue by applying a light film of grease to prevent the flap from scraping the sides too badly.  It's running pretty good now.  I just need to get a new AAR sourced and installed.  I have to manually introduce additional air on cold starts but that ain't so bad.

Now I can focus on the suspension.  This car rides like crap.

[Captain Obvious]

Great! Wonder why it was so far out of whack... Do you think the PO was in there messing with things?

And as for the suspension, I went through all mine a while back, and the night and day difference was amazing. It's so much better now!

[mentalite]

23 minutes ago, Captain Obvious said:

Great! Wonder why it was so far out of whack... Do you think the PO was in there messing with things?

And as for the suspension, I went through all mine a while back, and the night and day difference was amazing. It's so much better now!

I think that there was likely funny business, Captain.  Then again, the manual states that there is supposed to be a retaining spring of some sort on the bolt which is missing.  Maybe engine vibration slowly backed out the nut (correct adjustment was tightening the nut)?  If it goes back out of adjustment I guess I'll know that's the case.

[siteunseen]

It's a weird looking nut locking clip similar to this but the ends curve inwards more.

[Captain Obvious]

I don't know if it's stock or a PO mod, but I've got a Nyloc style lock nut on mine. Small open end wrench on the flats of the adjuster screw, back off the lock nut a little, turn the adjuster with the open end wrench, and then retighten the lock nut.

[gwri8]

This is what is on my spare. I think it's original.

[siteunseen]

There you go!  That's what mine has.  Thanks Greg.

I've maxed out my LIKEs for today, I'll have to wait until tomorrow to like you.  That's what I used to say in high school, laying with the unpopular but good looking punk rocker girls.

Edited February 10, 2017 by siteunseen

[Captain Obvious]

Cool. So mine is stock, but my tamper resistant clip has walked off somewhere over the years.

Note that in 78, they changed all that (except for California). In 78 they cheapened up the BCDD and removed the altitude compensating portion off the bottom for everyone except CA. Presumably, either they argued that only CA had enough "in-state" altitude changes to warrant the compensator, or they just decided that it would be more costly to go through all the CA qualifications and certs so they just left that state alone.

Anyway, the whole thing got shorter, and the adjustment screw looks different. I have a non-CA version here if someone wants to see that.

[mentalite]

I was sure that I had it nailed down that my Aux Air Regulator was bad.  I bought another one which exhibits the same characteristics as the original so I thought I'd better check with you guys to make sure my diagnosis is correct.

My understanding is that in cold conditions the AAR should be in the open position to allow additional air into the throttle body.  As it warms the valve closes, stopping the additional air flow.  My test for these has been to put them into the refrigerator and then the freezer to see if the valve is in the open position.  In both cases the valve only opens slightly.

Less than 0 degrees F in the freezer:

And this is the extent of the opening:

I'm expecting this to be fully open at this temperature.  Is my expectation valid?

[Captain Obvious]

In my experience, your expectation is not valid. If that thing was completely open, your idle would be at 4000 RPM. That opening you've got on that one should be plenty to raise the idle to a high "cold idle" level. The important part is that it completely closes when hot, or the idle will stay high.

Mine went intermittent. Sometimes the idle would slowly creep up to cold idle level even after the engine was warm. And then it would slowly drop back down as connection was made.

[mentalite]

Thanks, CO.

Well....it must require more openness than my photo shows.  Installing with it open to the degree shown doesn't provide the additional RPM for a cold start.  In fact, no additional RPM than I can detect.  It'll choke and sputter at around 400.  If I loosen the hose clamp and manually introduce additional air by pulling the hose off the AAR a little, then the RPM rise allowing a cold idle.  I pulled all the hoses and the T to check for obstructions and everything is clear.  I'm back to believing that the door isn't opening far enough.