carb question (Holley)

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More timing = throttle blades being closed more = less air flow by the boosters.

Timing will most definitely affect the amount the blades are open to maintain a certain idle rpm. Not enough you can and will get booster draw at idle. Seen and fixed this many times with the total timing crowd. Try timing a car with initial set at 0* and then again at 14-16, those two initial setting have VASTLY different carb idle setting profiles.

Here's what I would do for the OP's deal.
Take the carb off and make sure the primaries are not open further than a square showing for the transfer slots. Google it if you need to see what it is.
Verify that the secondaries are closed up.
Set initial timing at 14-16. D this with the engine OFF, ignition on. That way RPM has no effect.
Figure out the booster dumping fuel. This may cure itself once you reset the throttle blades for the transition slots. Float level, sinking float, etc.

Plug everything off that has vacuum at the source, carb, intake manifold etc... not at the end of a hose. Isolate the carb, intake tract from anything peripheral.
 
Hey sorry guys I went out and tore the carb down and got it soaking in a bath of carb cleaner at the moment- there was some build up on the metering plates around a couple holes in them as well as the base gasket being saturated with gas

FIRST - this is a new engine with 12 miles on it (6 nice- 6 spirited)-

the carb I bought off Ebay as a rebuild-able core it had sat for 5 years on a shelf prior to me owning it (so the PO said)

I didn't notice it on first start up BUT I had a few things wrong (installed the dizzy 1 tooth advaced) this was also fixed and was timed to TDC with the engine off -

here is what I did on first start up- rotated the balancer to 12* BTDC(thinking it was TDC) and stuck the dizzy in at No.1 cylinder and that is how it's running in the video... maybe I should redo that??

I just found a video on my phone it has 18" of vacuum @2,250rpm

the throttle blades were the first problem I took them apart and didn't take notice while reassembling them so they were stuck open a bit to far- took the base plate off re adjusted the blades lower and reinstalled and then the current problem started and still exists

Also can't have the vacuum advance hooked up cause once it is the engine revs to 3,500 or so SO I have the initial timing set W/O it at 32* while it's running @ 2,000rpm

video of the first start
[ame="http://www.youtube.com/watch?v=V4louTe6JF8"]1983 Mustang HCI 306 first start up - YouTube[/ame]
 
crackedback said:
More timing = throttle blades being closed more = less air flow by the boosters.

Timing will most definitely affect the amount the blades are open to maintain a certain idle rpm. Not enough you can and will get booster draw at idle. Seen and fixed this many times with the total timing crowd. Try timing a car with initial set at 0* and then again at 14-16, those two initial setting have VASTLY different carb idle setting profiles.

Here's what I would do for the OP's deal.
Take the carb off and make sure the primaries are not open further than a square showing for the transfer slots. Google it if you need to see what it is.
Verify that the secondaries are closed up.
Set initial timing at 14-16. D this with the engine OFF, ignition on. That way RPM has no effect.
Figure out the booster dumping fuel. This may cure itself once you reset the throttle blades for the transition slots. Float level, sinking float, etc.

Plug everything off that has vacuum at the source, carb, intake manifold etc... not at the end of a hose. Isolate the carb, intake tract from anything peripheral.
Click to expand...
I see now where you are coming from. Its the affect, or over affect of incorrect timing that would make a person over compensate with the carb adjustment(idle). Similarly if they had the idle misadjusted the mechanical advance would throw the timing off. I agree. I had thought you were saying the timing(directly) would cause the fuel to pull over. :violent1: Sometimes it doesn't get through right away. (that's me on the left!)
 
Lonewolf3165 said:
I see now where you are coming from. Its the affect, or over affect of incorrect timing that would make a person over compensate with the carb adjustment(idle). Similarly if they had the idle mis adjusted the mechanical advance would throw the timing off. I agree. I had thought you were saying the timing(directly) would cause the fuel to pull over. :violent1: Sometimes it doesn't get through right away. (that's me on the left!)
Click to expand...

No sweat, all good. That's it in a nutshell. One causes issues in another systems area. I've found that about 90% of idle issues aren't really carb related. It's usually an ignition issue if between the two systems.

Bottom line, it's fubard right now. What the OP has for vacuum at 2K+ doesn't mean squat, it's irrelevant. You MUST get the idle down and on the actual carb idle circuit before you can make any kind of transition/enrichment circuit (PV) decisions/choices.

I'll ask one last time before I'm out... what's the initial timing? Not the timing when you have it revved up to 2000 rpm. You'll chase your tail until you get the initial somewhere close
 
SO what crackedback is basically saying IS that if there is not enough timing it can cause a fuel draw from the boosters?
 
It will NEVER run properly at TDC for initial... Unless you need to smog test it... :)

I have a 340 with a bigger cam, MUCH bigger, than that one and it idles all day long at 800rpm. Crank up the initial. You'll have to limit the mechanical in the distributor to hit your total number. Don't worry about total right now and don't drive the car until you fix the total timing issue after you have the initial figured out. I'd just grab the distributor and give it a good turn to advance it, start the car, if it doesn't kick back on the starter, turn in some more, shut it off and start again. Do it until it drags on the starter.

Long cranking time, real dirty/black carb venturis, are an indicator of not enough initial. My cars, even with huge cams light off with the flick of the starter, no extended cranking. One exceptions is if the bowls are dry, nothing starts that way.
 
crackedback said:
It will NEVER run properly at TDC for initial...
Click to expand...
OK I will retime it with the engine off to 12* for a start like it was in the video..

OK I will give it a try! Thanks guys!!!- you've been more help than most of the Ford Chevy guys I talked to!
 
zac_F71 said:
OK I will retime it with the engine off to 12* for a start like it was in the video..

OK I will give it a try! Thanks guys!!!- you've been more help than most of the Ford Chevy guys I talked to!
Click to expand...

Put it at 16*...
 
Make darn sure your throttle cable isn't holding the plates open. I noticed you had to pull it down when you started backing out the curb idle screw. Maybe disconnect it to make sure.

Do the timing first, then disco the cable
 
crackedback said:
Make darn sure your throttle cable isn't holding the plates open. I noticed you had to pull it down when you started backing out the curb idle screw. Maybe disconnect it to make sure.

Do the timing first, then disco the cable
Click to expand...
I turned it down in the video cause I had it set high for the first start (so it would stay running) it was at 3,000 or so til I turned it down in the vid- the cable isn't holding it open(the cable has a integrated return spring) I have checked and re checked all that and now have 2 additional return springs on it

the base plate does have play in the primary shaft (with out the springs hooked up on it) so that could be a possible vacuum leak here...

the only things I can think of for vacuum leaks are the insides of the intake gaskets and the carb base plate primary throttle shaft
 
fingers crossed I'm borrowing a friends dyno street avenger carb this weekend SO I may have a known good carb to try out here!
 
fixed it- I'm going to blame the Quick Fuel needle and seats it runs great idles at 750-800 and SCREAMS when you put your foot in it! Thanks guys for all your help!
 
Nice that you got it sorted out. Get that timing set up and nail down your total and have some fun with it!
 
crackedback said:
Nice that you got it sorted out. Get that timing set up and nail down your total and have some fun with it!
Click to expand...
tis done!

it has a part throttle bog but I'm not going to touch it right now I can pedal threw it and then it gets real fun!- posted a vid in the general discussion area..

it idles great even cold with out a choke it will stay running
 
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