84 sedan project (beginners luck)

[Murdoc1905]

So I rechecked the timing at 1600rpm and it was at 10 from the bottom. Not sure why it changed. I did hook up the 10" and 4" electric connections when I tested it the 2nd time thou. On the bright side the carb teardown and subsequent cleaning made the stepper motor work again. I did have a spare on standby for testing otherwise but it seems to have worked itself out. When I initially started the engine it was in high idle at around 1800-2000 and I could not even see the timing mark with the timing advance vacuum hose hooked up, after I removed it and plugged it it dropped to 1600 and the timing mark showed up at 10.

[AMC of Houston]

Great!   I love it when expensive parts magically start working again!   Sounds like you have the timing close enough - If your sticker is still on the firewall, I'm guessing it said 9 degrees, +/- 2 ??

[Murdoc1905]

During high idle when I first turn the car on the pulse air system passenger side is going pretty crazy, I've always heard these pretty much don't do anything so should I be worried?
https://youtu.be/WikgCP5Fr0w

The engine running.
Old
https://youtu.be/9v4o_KzsGDk
New
https://youtu.be/TYuHMnDyw10

Once I shut the engine off it sounds like a lot of ticking, I imagine this is pretty normal. But just to be sure
https://youtu.be/LQYz5o8Cy8g

I've noticed a bit of white smoke I believe coming from the pcv filter in the air cleaner assembly, and after I shut of the car for a bit I noticed white smoke inside of the carb. Could this be piston ring blow-by? There is a bit of smoke coming from the exhaust manifold because of the oil on it, I don't think the rtv held at all and it's leaking in the same spots.

[AMC of Houston]

May have one of the check valves on the pulse air system not "checking".   They are supposed to keep air from flowing back into the filter housing.   If one of the air filter housing tubes is all rusty inside from exhaust moisture backflow, that may be the issue.

The ticking is probably just the metal bits cooling down.   Its not running too hot, is it?

White smoke in the carb is just fuel evaporation.   Make sure you don't see any fuel drips from the venturis after you shut off the engine.

You really should go with an aluminum valve cover.   I fought with a plastic cover on my '85 for 200,000 miles before I finally bit the bullet -- I should have done it way sooner!!

[Murdoc1905]

May have one of the check valves on the pulse air system not "checking".   They are supposed to keep air from flowing back into the filter housing.   If one of the air filter housing tubes is all rusty inside from exhaust moisture backflow, that may be the issue.

The ticking is probably just the metal bits cooling down.   Its not running too hot, is it?

White smoke in the carb is just fuel evaporation.   Make sure you don't see any fuel drips from the venturis after you shut off the engine.

You really should go with an aluminum valve cover.   I fought with a plastic cover on my '85 for 200,000 miles before I finally bit the bullet -- I should have done it way sooner!!

The pulse air system wasn't doing it before I rebuilt the carb and re-did the vacuum tubes, there is no rust in the tubes. Is this the check valve?


I can't tell if it's running hot or not as my temp gauge went out. It wasn't hot before it went out, it was right in the middle.

The fuel evaporation makes sense as I dumped fuel into the carb to start it so that's a relief.

I plan to get a quality valve cover and proper gasket, this was just a temporary to get it thru emissions so I can get it registered.

[AMC of Houston]

That's one of the pulse air control valves.  They're supposed to control the air flow based on the vacuum signal to it.   Could have a problem with one of those, or the vac switch controlling the vac signal to it, or the ECM circuit controlling the switch.   There's about a 4-page troubleshooting chart/procedure in the manual if you want to bother.

The check valves are further down right on top of the metal pipes going to the converter.   I can see one in the shadow in your pic.

[Murdoc1905]

Fixed the temp sensor. Once I found out where it was lol, need to add windshield washer to the list of things to fix. Tuned the carb proper and took it higher than I made it last time, no issues that I could see. Waiting on a tach to get the carb dialed perfect for the emissions then I'll see how that goes.

[Murdoc1905]

Put a new heater control valve in, hopefully this one doesn't leak.
Took the old one apart in case people wanted to know what it looked like.
https://image.ibb.co/gb1j0U/0914181949.jpg
https://image.ibb.co/fiAu0U/0914181950.jpg
https://image.ibb.co/mApREp/0914181950a.jpg
https://image.ibb.co/fYia79/0914181952.jpg
https://image.ibb.co/jVfBfU/0914181952a.jpg
https://image.ibb.co/j0Mv79/0914181952b.jpg

Still waiting on my tach to arrive so I can accurately tune the carb and timing.

[Murdoc1905]

Is there a special way to take the side view mirror off to tighten the screw that holds the housing on? I don't want to break anything trying to pry it off. Also is there a way to fix the mirror adjustment cables if they are sticking? Can I poor some wd40 on them?

[mudkicker715]

Omg this han't lube in years. Do what you can before you break it.

[Murdoc1905]

Okay so I got new shoes for her, took her for a little drive and noticed a lag response going from idle to throttle at nearly any speed. So I think it's the accelerator pump not set up properly after I took it apart. So I'll try to adjust it. It feels like there's a "dead spot" in the low range of the throttle pedal.

[Murdoc1905]

Did a little adjusting with no luck until I realized that the plunger and the metering tubes are seperate adjustments lol. I just kept loosening the two screws and just adjusting the plunger, throwing the metering out of wack more and more. Still have a little bit of tweaking to do, but the dead spot is smaller now. It's weird thou, if I slowly increase throttle it lags more, but if I more quickly press the throttle it lags a lot less. I imagine the plunger is fine, I just need to do a little more tuning on the metering side.

[AMC of Houston]

A couple of other items that could cause a tip-in hesitation are timing (which I think per your earlier posts you have set OK), and the vacuum advance not working properly.

Just some other things to check if getting the carb settings dead-on doesn't fully cure it.   As I mentioned earlier, BBD's are very picky about pump height and metering rod settings; so I hope that's it.

[Murdoc1905]

Re-checking the timing I'm pretty sure it's off by a lot, and the vac advance is really just trying its hardest to get it somewhat close. How do I adjust the timing? I have tried to rotate it, no luck, tried to unscrew the two screws up top but that just holds the cap on. Is there a bolt I'm missing? Every video I watch either its already loose or not even close to the same type.

[mudkicker715]

A single bolt under the dissy that goes into the block. It has a wishbone "washer" under it. Its either 1/2 " or 9/16".

Probably 1/2".  There is a special wrench to loosen and tighten.  That bolt should only need a 1/2 a turn to move the dissy. Mark the base and engine block to see where you started, incase you want to return to where you were. A timing light is useful here.