Matt, You ran well enough to put me on the trailer at Mason Dixon!!
People who run Holley's generally have the same story as Bill. He gave you a nice write up but I can give you one that is a lot shorter:

Step #1 -Remove Holley
Step #2 - Install 500 Edelbrock
Step #3 - Drive car

There you have it. 3 steps and ready to race!!

Just teasing everyone a little! I certainly am not a "tuner" by any stretch. The guys that have responded are the experts and I think their info will help a lot of people that want to run their Holleys.

Good Luck,

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Haha it's all in good fun, Rick

Some minor progress updates: Innovate wideband sensor has arrived, but I've been too busy and short of daylight to get it installed yet. It's a bit more involved to wire it in than an AEM unit, but I can't abide digital displays when they're avoidable so I took a pass haha.

The temp dropped back into the low 40s here and my drivability went back into the toilet. Even when warm, still almost died when opening the throttle quickly and bogged between 1500-2000. Tried to futz with the idle screws for max vacuum, and found out that the idle circuit was being bypassed somehow... engine didn't die with screws all the way in. Pulled the carb again, and the base was covered with fuel (some dribbled out the front, usually plugged, man vacuum port), and the manifold had a nice puddle.

Now I know some of that comes from repeated pump shots into a cold manifold, but it seemed quite excessive. Holley tech support suggested checking for a busted power valve.

The PV seemed fine, but I swapped it for a 6.5" I had lying around just to be sure. I reset the idle and fast idle screws as per earlier suggestions, and the acc pump using the method in the Dave Emanuel book (great reading, btw!).

Started it up, and warmed up, she's making 16-17" of vacuum in park at 1100 RPM (idle set for max vacuum). I couldn't get the idle to drop any lower, even with the main butterflies all the way closed, so I figure I'll have to pull it later and close the secondary stop a bit more. Took it on the road though and it drives like a dream now--no flat spots, plenty of power, pulls all the way up to the redline on the primaries (black spring keeping the secondaries closed).

I'm chalking it up to lack of a rich condition from whatever was dumping fuel, and the 6.5" PV being better suited to my motor in general. Current annoyance right now is a tendency to stall out when coming to a complete stop in gear, or when switching from P to D without goosing it a little. I don't want to turn up the idle any higher, it already thumps into gear and drops about 600RPM. I suppose it's time to start experimenting with base timing and see if I can get it to idle stronger and slower.

I'll get some better numbers and vacuum readings to move forward with, but just wanted to update and thank everyone again for their help!

Sounds like you are getting closer.

If you want to experiment a little now without removing the carb (or feel a bit lazy) the stop attached to the secondary vacc linkage can be tweaked a bit with a pair of small pliers...But for best results you will want to measure the distance of the secondary plates in relation to the transition slot with feeler gauges for accuracy.



-D.Idiot

Red,

Are the transfer slots still covered in both primary and secondary barrels? If not get them covered, but adjust throttle plates so they are not closing tight in the throttle bore. This will wear a groove in the wall after a while, and raise hell with tuning later on.

Covering transfer slots will eliminate almost all flat spot problems at low speeds.

Shine a flash light up from the bottom of carb, and look for a hint of light passing around the edge of throttle plates. The reason the engine won’t settle down is idle is still a little rich, also the transfer slots are probably showing again, and by adding a little air past throttle plate being cracked open too far by idle speed adjustment. In other words the idling engine is trying to digest fuel from idle circuit, and some additional fuel from transfer slot that normally come on line once the car starts moving and during small throttle openings such as cruising on flat ground at low rpm

Once you get the o2 sensor up and running, you can tune idle mixture screws under the hood with a volt ohm meter by placing black lead on negative battery terminal and the red on at the o2 sensor to harness connection. The o2 directions will explain which scale to use. I have been tuning idle and transfer circuits on my chunk of Holley junk with a volt meter & vacuum gage; far superior to rpm & vacuum method.

In park idle needs to get below 1000 rpm, better still 900 rpm because the mechanical advance is starting to kick in boosting idle speed still higher. The fix for camed up engines that need to idle 1000 rpm or higher is a recurved ignition advance. The goal is to have no mechanical advance few hundred rpm above the engines higher in park idle. Also in some situations a looser torque converter may be necessary to quell the harsh park to “Râ€￾ or “Dâ€￾ shift. But, before we jump over that cliff, there is still a lot of tuning to go; remember cheap or no cost stuff first.

That 6.5 PV also killed a flat spot at higher throttle opening when running on boosters trying to accelerate. In other words the enrichment came on sooner before mixture went too lean at WOT.

[quote]'m chalking it up to lack of a rich condition from whatever was dumping fuel, and the 6.5" PV being better suited to my motor in general. Current annoyance right now is a tendency to stall out when coming to a complete stop in gear,[/quote]

Maybe, but with o2 sensor you will know exactly which way to go leaner or richer. I’m going to hold off advising idle mixture tune until that o2 sensor is up and running. Some of the problem is cold intake surfaces.

For now you could cobble up some sort of cold air shield to help keep manifold warmer.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC