Altighty. UPDATE TIME.
Everything on this rig was pretty dirty but after cleaning, lubing, new batteries it turns out almost everything works great. I had to rewire the rear air conditioner as somehow the romex wiring in the wall was shorted together. . . weird! Anyhow I have everything working.

List of what I've done:
Batteries $160.
Tires $1150 ... installed at my home
Complete lube. Oil, trans, chassis, differential and coolant $50.
Converted Dash AC to R134a from R12 $50.
Tune up= Plugs, wires, cap, rotor, air filter and pcv valve $50.
Timing adjusted to 10 degrees advance.

The loping idle has gone away and I did find a disconnected vacuum hose to the carb which I replaced.


PROBLEM!!
I took it to emissions and it failed TWICE on the HC (hydro carbons) at idle and load.

Before the first test, here is what I did:
Replaced plugs and wires and did all fluid changes.
I checked the Egr valve and it is functioning properly (holds 10" vacuum indefinitely and rpms drop significantly when vacuum is applied in place of vacuum hose).
HC reading first test: Loaded 392, Idle 509

Before the second test I replaced the pcv, air filter, rotor and cap. I also advanced the timing to 10 degrees.
I then added 3 bottles of rubbing alcohol to the gas tank and here are the reading on the second test: Loaded 748, Idle 781.

So all my efforts to pass had the effect of doubling the hydro carbons emissions.

Anyone have any advice on this? Should I mess with the timing?

 

Altighty. UPDATE TIME.
Everything on this rig was pretty dirty but after cleaning, lubing, new batteries it turns out almost everything works great. I had to rewire the rear air conditioner as somehow the romex wiring in the wall was shorted together. . . weird! Anyhow I have everything working.

List of what I've done:
Batteries $160.
Tires $1150 ... installed at my home
Complete lube. Oil, trans, chassis, differential and coolant $50.
Converted Dash AC to R134a from R12 $50.
Tune up= Plugs, wires, cap, rotor, air filter and pcv valve $50.
Timing adjusted to 10 degrees advance.

The loping idle has gone away and I did find a disconnected vacuum hose to the carb which I replaced.


PROBLEM!!
I took it to emissions and it failed TWICE on the HC (hydro carbons) at idle and load.

Before the first test, here is what I did:
Replaced plugs and wires and did all fluid changes.
I checked the Egr valve and it is functioning properly (holds 10" vacuum indefinitely and rpms drop significantly when vacuum is applied in place of vacuum hose).
HC reading first test: Loaded 392, Idle 509

Before the second test I replaced the pcv, air filter, rotor and cap. I also advanced the timing to 10 degrees.
I then added 3 bottles of rubbing alcohol to the gas tank and here are the reading on the second test: Loaded 748, Idle 781.

So all my efforts to pass had the effect of doubling the hydro carbons emissions.

Anyone have any advice on this? Should I mess with the timing?

 

try a couple of bottles of fuel additive, you may need to look at the cats...

 

set the timing back to the factory setting, it is timed for the best emissions there will be a guide under the hood that will tell u the timing, it could also be blowing oil, the cats could b plugged too

 

I believe you are going to find a vaccm issue. But, if I was going to go to all the trouble to do some of the more intailed repairs on the carb I think I would find a emissions approved after market electronic injection to replace the carb system. they get better economy and are fairly trouble free once set up. as for the motor being close to worn out that is totally dependant on the accual condition, if it is not smoking, knocking, rattling, or foulling plugs and the compression is good I would run it. goog luck and happy motoring.

 

it is a fuel injected unit already

 

It is a carburator with electronic injectors into the carb. I'm not sure what you call this setup.

I am not sure about the vacuum leak. There's only 4 vacuum hoses I can find in this setup and thay are all holding strong and tight. No vacuum leak at carb base either.
Where else could there be a vacuum leak?

What is the likely hood that the cat convertor is bad? Would it be possible to pass without the cat functioning or would I have unpassable high Hydrocarbons on a 454 without it's help?

 

you will never pass without the cat, i would set the idle back to factory, take a vacum test , under the hood the shoud be a chart with plug gaps, timing adv. and vacum pressure, what you have is called a throttle body injected motor, they are fairly simple to work on, ill bet th O2 sensor has failed too, it will make the truck run rich, the easiest way to tell if a cat is gone is when doing a passing menouver, the exhaust smells like rotten eggs, you will need somebody following you to tell though, or u could pay a mechanic to tell u if it is bad, it would be good to take it to a mechanic to diagnose it b4 u throw a bunch of cash at it replacing things but a mechanic can hook it up to a comp and tell u what is wrong right away

 

Thats called TBI or Throttle Body Injection

I would be suspicious of the cats

 

Spent a couple hours this mornin replacing the Catylitic Convertor. Set the timing back to "factory specs" which apparently is supposed to be 6 degrees advance and ran it through emissions.
SO JUST TO RECAP That's new spark plugs, wires, distributor cap, rotor, O2 sensor, catylitic convertor, 3 bottles of alcohol in tank, all 8 cylinders reading 143-146 psi on compression test

AND IT FAILED AGAIN!

GOOD NEWS is that it finally passed the load test for hydrocarbons, but the idle test is WAY TOO HIGH!! The Carbon Monoxide on the idle test jumped real close to failing too which was a surprise.

Wits end..........................................