Heres a video I just shot taking it for a test run.. I'm trying to take off slowly all 3 times but it wont go anywhere until I give it to much gas and then it takes off to much. This would be deadly in wet road conditions.

I'm not sure if they processed the video yet so you may have to try later.

http://www.youtube.com/watch?v=uswD...re=channel_page

there's nothing wrong with running a gear drive

Here's something I just noticed and I believe its contributing to the off idle stumble.. First let me explain in more details whats happening.. If I accelerate real slowly off idle the motor wont respond at all until I start to give it more pedal and then it kicks in and takes off but that causes a big jolt. With that being said, if I look down the carb and slowly apply the throttle I notice there is no pump shot from the primary squirter. I'm guessing thats because the pump doesnt respond with such a slow pressure being applied. That being the case, what makes up for that?

This could cause a lean stumble. The pump is a positive displacement deal, so any movement of the diaphragm should cause fuel to be expelled from the shooter- if the check ball or valve is working correctly.

There needs to be about 0.015" clearance between the pump arm and the pump lever at WOT, but there also needs to be instantaneous actuation of the pump lever/accelerator pump as soon as you touch the throttle. This is adjustable, too.

If I apply pressure a little faster or mash the pedal it will shoot out but a very slow "sequeeze" of the throttle wont do anything.. I have made adjustments already but it doesnt matter because a very slow squeeze of the pedal isnt enough to activate the pump enough to do anything no matter where its at... It dribbles a drop or two but thats about it.. Is this the main reason for most off idle or part throttle stumbles?

UPDATE

I just solved almost ALL of my issues.. I followed F-BIRD'88 instructions and almost every single issue I had is gone! The car has absolutly no hesitation and pulls real hard through all gears now. What a rush to finally feel the power has had all this time.

I do have one small isuse left.. The idle is perfect at start-up and after it warms up but when I go for a drive it picks up to about 1500rpm's and wont kick down.. If I bring it back down to 900-1000, its to low when I start it up again until I go for a drive?

Readjust the idle mix screws only after the engine has reached full operating temp.
Pull the intake and block off the exhaust riser passages. The 2101 performer manifold is getting too much plenum heat. Too much intake manifold plenum temp difference between cold and full operating temp. Possible manifold vacuum leak that gets much worse after warm up. the performer manifold is famous for runing too hot unless the heat passages are blocked off.
My need the holley under carb heat shield also that protects the carb fuel bowls from the heat of the manifold runners just under. works very well on low rise manifolds.

Then, use the choke w/fast idle system for cold engine operation to aid until it warms up. You have a carb/manifold (excessive) heat management issue.
Good to hear its running much better otherwise.

The curb idle screw is all the way out now but I'm still at 1200rpm (wont adjust down anymore).. Do I need to close the secondaries slightly? I have them set at .020

The 900-1000 I stated above is when it was in gear but when I put it in neutral it climbs to 1200..

Well, congrats- finally! You do realize that from the first page of the last thread titled, "Manifold Vs Timed Port Vacuum", we've been trying to get you to put a timing light on it? lol

At least now you have a hint as to what type curve is needed- a lot of initial and in by prolly not more than 2500 RPM.

There's no need to run all 36-38 degrees all the time or rigging up toggle switches to power up the ignition while the starter's spinning unless you find it's absolutely necessary or just don't feel like tuning it further.

In any event, you now know it needs a lot of timing early. You could work on this premise and style a curve to give that as well as a decent amount of timing at start-up. Heavy centrifugal weights and/or light springs with the total advance limited to 36-38 degrees.

If you have to go so light that the springs don't supply sufficient force to return the weights to their "closed" position, then think about either an MSD box or locking out the centrifugal advance. Otherwise, there's still some work to do.

But you really do need a timing light if you plan on tuning the timing curve further.

EDIT- This engine has a Performer? I take it it's because of hood clearance issues? That intake isn't the hot set-up, but if it's all that will fit...

Something else I realized is that the exact set-up of this engine was never really spelled out. It came to be known it had a Summit (Holley4010) carb, one of the Thumper? cams, but a LOT of info wasn't known- even now.

I don't see that it has been addressed here yet, but have you checked the fuel pressure at the carb inlet? 5 psi max...5 psi max...5 psi max...5 PSI MAXIMUM. More pressure will not make any more horsepower. This is not a fuel injected system. All you need is enough pressure to move fuel from the tank to the carb inlet without over-powering the needle and seat and blowing raw fuel into the motor. 5 PSI MAXIMUM.

I'm gonna keep bangin' on this until everyone gets it. 5 PSI MAXIMUM FOR ANY MODERN 4-BBL CARBURETOR is all it takes.

Yes, the intake is a #1201 and I can only fit a 1.5" air cleaner under the stock 427 Big Block hood so I am working on this white hood with scoop now.. My 4" air cleaners still touches the bottom of the scoop but since I have solid motor and trans mounts, it doesnt torque much.

The funny part is that I never touched the timing, its still at 18/36.. It all had to do with opening up those secondaires to .020 and plugging my PVC back in and that totally cured the stumble and it also launches better and pulls alot harder too.. I didnt bump my timming up anymore because I cant get the idle back down below 1200. If I dial more timiming into it, I'm sure it will climb even more. I know there's still more power in this motor but I'm really happy I finally found alot more of it and the stumble is gone..

Thanks for all the help!!

Lemme see if I'm following you here.

Now, you're saying I need some kind of psi to get the fuel from the tank into the carb and I get that, but what I can't seem to find out is how much force or push does the gas need to make it all the way to the carb from back where the tank is- so, what would your recommendation be for this? Do you think 7 or 8 psi will be best? I want my **** to be FAST, so I'm thinking maybe 9 would be even better.

Yes, its set right on 5psi

I'm sure you know all about the drop-base for the BBC/'Vette 4 bbl that gives some extra clearance- likely that's how you're getting as much filter and clearance as you are now.

I totally missed the part where the PVC was mentioned, so I hadn't taken into account that it wasn't there. My bad.

Go ahead and close the secondaries some, you can always go back if the results aren't what you want.

This carb has the Idle Ease (or whatever they call it)? Just wondering.

No, this one doesnt and it only has 2 primary idle mixture screws.. Its running pretty good right now so I'm going to hold off on doing any more tuning until my new Demon comes in and then see how that one runs.. At least now its drivable and with some good power. I can mash the pedal from a stand still and it will start getting sideways before hooking back up and launching and then if I short shift into second it will chirp them pretty good too