Need some FE Help

I had this posted on the FE site. I'm guessing since the answer isnt obvious, and it wasnt a question about a W-code 427 Mustang, or a grade of oil, or a good cam choice, nobody posted their thoughts on this. I tried to explain...towards the end. It involves a little troubleshooting, but it seems the answer is right in my face but I need another set of eyes. I copy and pasted it below. I know its a bit wordy. Comments and suggestions welcome, i want to make sure i am on the right track.

Since the garage queen is out getting some fab work done, it was time to work on the neglected F-350.

I was tired of changing and cleaning fuel filters every tank of gas so i pulled the offending dirty one for a flush and purge. The fuel pickup didnt have a pickup sock/strainer or anything. Just a steel pipe. I dont think it can get the last gal or so of gas. The tube had lots of corrosion and rust and gunk inside of it. I took a 1 ft legth of baling wire hooke to a cordless drill and spent half an hour on it till it was open and clean. The float was full of gas with a crack in it. After brainstorming, I couldnt think or something to seal the crack. (only later that day did i read the forum and saw an idea to use solder) So i did a typical country boy fix. I hacked open a 1 barrel carb and stole the float. Some delicate tie wire work and viola! Then back to the tank, a 2 ft length of logging chain, a garden hose and i went to work. Good thing i didnt have a picasso mural painted on it to worry about. 2 hrs later i think i got all the sand, grit and rust out of it. Now how do you dry a wet fuel tank when its below freezing outside? Set it on the coal stove of course! (use safety glasses and your handy OSHA booklet)
Got it back in and strapped up, sparetire aired up and re-hung. Plugged in the guage wire to the sending unit. New Fuel line to the steel line. Next i did away with the pre-pump filter. It still has the canister type on the pump itself and a new in-line metal type between carp and pump. The new lines were increased to 3/8ths from main steel line to pump, and from pump to carb. The purpose of that exercise was to clean out the crap, eliminate any pinholes that may be present in the fuel lines, and make it easier for the pump to suck gas from the tank(s).

So now that fuel supply isnt a problem, (and the gas guage amazingly works) time to re-attempt my failed TBI/duraspark conversion from this spring.

I had the new TBI coil and HEI 4 pin wired and ready for Sun morning. The Duraspark dist is a new rebuilt from napa. (sorry, not a Faron recurve) But new compared to the 40 yr old dist with Allison electronic conversion it had. Set motor on #1, 14 deg BTDC on balancer, and pulled the old one. I noticed the oil pump shaft looked funny in the hole. Decided to make it right with my new handy dandy telescopic magnet. Much to my horror it pulled right out without the press washer (it wasnt there) So before panic set in, I wiped it down and tried it on the new duraspark. It almost didnt fit, but when it did, it fit tight as hell. Disaster averted. Dropped in the new one, realized i was 1 tooth off, reset it again and bolted in the clamp. Crimped in the new wires and attached everything. Started up on first crank.

Now to my questions.

The carb i am running is quite unconventional for you guys. I am certain it is a Holley 660. I got in back in 04. The seller and myself thought it was a 625 race carb. New in the box. Since i am smarter now and have since researched it, i know what is is now. It just doesnt have 0-4424 on the air horn. Its been on the truck for over a yr now. It responds well to adjustments and made the truck run so much better.

While setting the timing, I tried to adjust the carb down off the idle screw. The truck is now set at about 18 deg BTDC and runns good there. (no ping or back fire and isnt labored) It is pulling about 9-10 hg of vacuum through the vac advance port. When i plug it to the dist, it then advances at an idle. I know this is not right. I think i am exposing too much of the transfer slot in the carb, creating more vacuum, in turn advancing the dist...all at idle. The A/F screws are about 3 turns out on each side. The idle is a bit irradic, moving about 100-150 every 20 seconds or so. But runs like a raped ape. But steady driving @ about 25 mph, you can feel the irradic idle.

Plug check before the duraspark was black and fuzzy, with dark brown ceramic. After the balls out run, they were clean, with a light caramel ceramic. I think the hotter spark and the better timing cleaned them up.

So back to the irradic idle. My research here leads me to believe I must start with drilling 1/16th holes in the primary blades of my carb. But i want that to be my LAST option. Once i go there, i cant undo it.

I have a 1406 and 1407 Edy i can put on it, and the 1407 may be a better option. But the my Holley has an adjustable acc pump (with red spring) and i have it adjusted more than most guys. the reason is my motor has a stumble at initial throttle open. Giving it more juice there fixed that. (last line in the chapter on carbs in Barry's book). The Edy lacks that type of adjustment. I dont have an edy kit with the fancy springs and rods. So I stayed with the Holley.

So as I close out my essay on my last 2 weekends, what would you guys do? Drill the primary throttle plates and hope that will cure the idle problem...and effectively give it more air so i can back off the idle screw...and it wont advance my dist at idle? Or should i swap carbs to the 1407 and fiddle with it to see if it cures the problems.

Unk known cam (probly a comp cam as there is s stcker on the firewall)
Performer 390 intake

tuning a carb is not a ... do this and it'll work fine .
Holley site has info plus some other carb companys , and thier not one quick answer and fixed either

I'll recheck their sites for any additional info they may have that i dont. I promise I am not looking for that ONE thing that will fix it, i am prepared to do a vary many multitude of things to get it running smooth.

First, a 660 is L4224 not 4424 and it has near 1 to 1 mechanical secondary throttles. If your idle screws are out 3 turns to simply allow the engine to idle then your carb needs more than a simple adjustment. The engine may have a vacuum leak somewhere else, also.
Opening the secondary idle speed adjustment a half turn will somewhat mimic holes in the throttle plate; (once the secondary off-idle slot shows under the plate you have gone to far).

Yep, i mistyped it, you are correct on the carb #, 4224

I think i will try to adjust on the secondaries to open it up for more air. I just dont recall any screws or adjustability on the secondary side like the idle screw on the primary side. Is it on the driver side or pass side?

Main goal is to get the idle screw backed down so it doesnt pull much if any vacuum at idle.

Vacuum leakes have been checked and rulled out at this point.

olschoolsteel wrote:Yep, i mistyped it, you are correct on the carb #, 4224

I think i will try to adjust on the secondaries to open it up for more air. I just dont recall any screws or adjustability on the secondary side like the idle screw on the primary side. Is it on the driver side or pass side?

Main goal is to get the idle screw backed down so it doesnt pull much if any vacuum at idle.

Vacuum leakes have been checked and rulled out at this point.

That secondary idle speed screw is accessible from the underside of the carb on the passenger side. Like a lot of Holley carbs, it may be frozen in its present position.

Do i need to pull it to adjust it then? Is the screw in one of those recessed areas in the base plate or on the exterior, near where the vac secondary would be. Either way, I'll try to get at it tonight.

Yep it's recessed on the baseplate. You might need to hit it with some penetrating oil to loosen/adjust it. It's a small/narrow standard screw

Where is the dist plugged into on the carb to get the vac signal? Isn't there a specific "ported" vac port that doesn't have vacuum available at idle?

Currently I have it plugged into the only vac port on the carb, on the pass side, just above the idle air screw. I havent tried using direct manifold vac/port.

It's been a long time since I fooled with a vac advance deal but I thought it shouldn't pull vacuum at idle. If it does it shouldnt be much. Sound right?

yea, i think thats the root of my problem. It has 9-11 hg of vac at idle, and when hooked up, advances the dist. I think the cause of the high idle is it wont get enough air, and i have to give it more idle at the screw. I dont want to drill holes in the primary throttle plates just yet, so i am going to pull the carb and try to adjust/open the secondaries to give it more air, and back it down off the primaries. Hopefully to lower my vacuum so it doesnt advance the timing at idle. Hope i explained that right...without contradicting my previous posts

jbozzelle wrote:It's been a long time since I fooled with a vac advance deal but I thought it shouldn't pull vacuum at idle. If it does it shouldnt be much. Sound right?

Full manifold vacuum to the distributor was very common before emission standards came to be.

If the idle is to high you certainly don't need MORE idle air flow. Try another carb which you KNOW to be a good performing carb from another running vehicle.

Doesn't someone make an adjustable vac advance can that you can set tension on the spring? Would that help?

I may be about to tell how ignorant I am of Holley carburetors, did the 660 C/S's have a vacuum port?

Dave.

The holley site only shows the driver's side to prove it independantly, but mine does...

Good point on the manifold vacuum. I should probly start there before i pull the carb and try the 1406 or 1407 edy carb...or try adjusting this holley.

jbozzelle wrote:Doesn't someone make an adjustable vac advance can that you can set tension on the spring? Would that help?

Most Ford Durasparks have an adjustable vacuum advance. Insert an allen wrench into the vacuum canister opening.

Dave,

olschoolsteel wrote:The holley site only shows the driver's side to prove it independantly, but mine does...

Good point on the manifold vacuum. I should probly start there before i pull the carb and try the 1406 or 1407 edy carb...or try adjusting this holley.

IMO, driveability will be enhanced with ported vacuum, as well the ability to control detonation.

JMO,
Dave.

I thought it was a 660 center squirter. I was corrected on the FE forum, it is a 450 CFM, but still designed for the 2x4 intake.

So I tried manifold vacuum, still pulled 12 hg at idle.
Pulled the 450 and put on a used rebuilt 650 vac sec Holley i had and the vacuum pull was way down at idle. It sounded OK. Turned it off and got ready to start tuning on it when i heard dripping. Hopped up and looked down the throat, and it wad dripping out of the squirters.
Pulled the 650 off and dropped on the 750 edy. Started and ran like a champ. Did some fine tuning. Pulls zero vacuum at idle, and didnt piss itself when not running.
Still had a little irratic idle and stumble at about 2k rpm. Thought about it for the night and the next day i swapped out the GM HEI 4-pin i used. Looks like i used one i pulled from the bone yard to set it up, but had a new one in the box. Hooked it up, drove the hell out of it. Plugs are clean and like new. I must have gave it a good work out. Sprung a leak in the 4 core radiator. Then spent the next day swapping in and fabbing up another new 4 core.

Thank you guys for the tips and areas i needed to focus on. When you stand for hours in your garage alone, its nice to bounce ideas off someone to make sure you are on the right track.

Good to hear that it's all sorted out.