I've been doing a lot of reading along these lines and I think right off the bat I might have a vac leak (i know the PCV gasket is seems un-good and the valve pulls out very easily), and possibly timing issues.

My mechanic adjusted the timing when I got the car and rebuilt the carb but for the life of him could not get the car to idle down properly. He's not a tuning shop, but has been building and restoring for 30+ years and really knows his stuff.

With so many small possible problems we just left it idling high and drivable while we work on the interior.

When we take the car out of drive and put it in park, the RPM shoots up past 1500 (even though it idles lower than that after warm up and choke fully open), and if we turn it off the engine runs on and shakes badly. It seems the throttle sticks a little. If it push it up a little manually, it will stay there, and I can push it back down in the same fashion.

So we added another spring to the throttle return and the throttle doesn't jump up when parking anymore! But now warm-up is a bitch, I have to hold the throttle or the idle will drop too much and it will stall. I screwed in the low idle screw to prevent that, but we end up at the same high idle state, only without the run-on.

If I adjust the idle to the point it will warm up, the idle drops from 1100 to 700 when I put it in gear, but any lower than that it it chokes and dies. I don't think park idle should be 1100 when warm though...

Electronic choke functions, I've watched it from fully closed to fully open as the engine warms.

Sorry for the long post... I am leaning towards a dizzy that needs some love, or additional work on the vac system. I just replaced the headlight hoses and still no luck, still need to change the rest though.


Any thought or guidance would be much appreciated. I've got Lars' papers on vac and timing but still need to grab a light gun

 

disconnect the main vacuum feed from the carb and plug it to see if there is a leak. spray the base of the carburetor with carb cleaner and see if the idle changes.

 

Got some carb cleaner today finally, I will try it out tomorrow. The carb base gasket was replaced when the carb was rebuilt a few weeks ago, so I hope that it all right.

The PCV bushing on the stock rocker cover seems... crappy. Any special way to remove it and replace it? Might it contribute to a vac leak as well?

 

Last time I had an idle that high, I swapped carb gasket, tightened down card properly, problem solved.

 

I can lower the park idle but idle in gear drops to near stalling

 

I located a vacuum leak with the carb cleaner on the steel vac manifold connection that goes to the brake booster. Not sure if that will help the starting issues. Even the crappy PCV valve gasket didn't rev the engine when sprayed!

On starting now the car doesn't hit a fast idle, I have to hold the gas for a bit until it has warmed up slightly. Choke is still operating properly. Is there a fast idle adjustment screw I can play with on a holley? It has a 600cfm Holley 6619-1 (4160 body). I have the Holley spec sheet, but I'd love to have a user manual for it

 

Chances of this being a carb issue are slight. You probably do have a vac leak somewhere

These cars are notorious for vac leaks.

Get all the info you need on your Holley here:


http://www.holley.com/TechService/Instructions.asp

 

Still having a hard time finding this old 6619-1

 

You really need to check out your engine as well.

Your carb is an early 70's emission carb designed for a bone stock 350. Holley doesn't make them anymore.

If your car has a cam, different heads or any other kind of modification from bone stock smog crawler, it will not run right.

 

We had some question as to weather the cams had been done, but the previous owner did not do it. The know the owner before that as well, and it is believed they did not either. The first owner only had it for 8 years, but no idea what they may have done in that time.

What can I do to determine if the cams were changed without pulling the covers?

 

It seems that a vibrating vacuum needle indicates overlapping cams, so the cams may have been done at some point in the past, possibly in the first 8 years the original owner had it.

I changed the wires and dizzy rotor/cap and all cyclinders are firing every single time now, and it has smoothed out a lot. With the new harmonic balancer I should actually be able to see the timing mark, and the dizzy recurve kit should get it running in top order. Still investigating the hard starting I am experiencing, and need to do a leak down test still. Investigating possibility of sticking valve in #8, which is also the only plug that was half/half when I swapped them. I think it is long enough now to re-read them and see how that one looks after a few hundred kms.

 

If the motor has been worked the stock timing may not be the right spec. This would cause hard starting. Try bumping it up a few degrees and make sure you're using the correct vacuum port for vac advance.
If its hard starting after its warm, look inside the carb for dripping after you shut it down. This would cause a flooding condition.

 

Now that I have a timing mark again and the recurve kit I will try again to time it to Lars' paper, including moving it to manifold vac instead of ported vac.

Should I HAVE to pump the gas to get it to start? I have to pump the gas to get it to fire up, and hold the throttle a bit to keep the rpm up for a few seconds to get it to stay running.

Old guy I work with suggested pulling the intake in the winter and making sure the exhaust crossover in the intake isn't completely clogged up as it might contribute with hard starting until the passenger side exhaust coil valve has opened all the way. Still starts not great after running hot, though I will see how it runs after a good jog with the new everything put back together.

I don't recall anything dripping in the carb, but I will check that as well.