anyone have any idea what could be causing my car to spit and sputter, and generally run poorly after about 3 grand? (my car=85 vette: l98 with holley 650, ebrock performer, holley red pump. stock 74 vac adv dist with accel coiil and module. 12 in vac.) if i take off slowwly it will generally run ok through the gears up to 50-60 so far,. i havent gone faster than that yet. but if you nail it will pull some off the line, barely turn the tires, and run like crap .it seems to really be running weak. i changed the accelerator squirter from a 31 to a 40 because it would die if you nailed it. i had to put a fuel bypass in because the red pump competely overpoweers the carb and fuel goes everywhere.(thought these things were regulated and would run great with a holley carb and not overpressurize the system.) i checked for vac leaks, but havent found any yet. set the timing to highest vac reading (12 in). still playing with the shift points to get them right.(at the tv cable) wth is next??????? HELP!!!!!

 

Check your plugs. Possibly fouled. ...It's the easiest/least expensive thing to check first. If that's not it...I don't know...other than timing is WAY off...

 

oh yeah, forgot to mention that timing is set at 12, seems to run the best there.

 

plugs are a light tan, i think that is good. possibly? any one else have any ideas? :confused: :confused: :confused: btw thanks '69 :)

 

do you have an electric choke on your holley? if so, disconnect the the 12volt side of it and wire the choke open. take it for a ride and see if the problem persists.

 

thanks, ill try that and let you know.

 

I am not sure about your "by pass" deal you have there with your fuel. Red pump should be good for 7 psi and your carburetor should take it. If you run blue or black pump than you need regulator because those pumps are putting out 14 psi. Make sure you getting good fuel flow and your flows are set correctly. You should also put timing light on and check you timing while you rev your engine to higher rpm's. If your distributor is not advancing enough, your car will run weak too.
Also, did you buy your carburetor new or used? Sometimes, if you have used one previous owner could do something to it and it will not run good (you should have it checked out by someone that knows carburetors). If you running new, than normally they run OK straight from the box and only minor adjustments are needed later on.
Ziggy

 

I went through alot the same problems you did and the problem sounds to be in the fuel or carb. Order a $20 Holley 3-port regulator for your setup. One port feed, one port to carb, one port return line to the tank. How is the fuel being sucked from the tank? are you sure its got a good setup to be able to get enough fuel from tank?

 

check to see if your secondarys are opening this could really hurt over 3000 RPM

 

hey zig, yeah i thought the same thing about the red pump. so i puulled off the by pass and tried to run it without. all that got me was an intake manifold full of gas (the outside around the carb) gas was a'shootin all over the place! i checked the timing when i set it, it was advancing. the carb is a brand new holley 600 vacuum seconds.

 

carbedc4, thanks for the info on the regulator, i didnt know they made that! that will help out im sure. im using the stock fuel line because i plan to go back to fuel injection in the future. in place of the old fuel pump i put a line in so i wouldnt run out of gas at a 1/3 or 1/4 tank. seems to get enough fuel to overpower the carb without a bypass, though.

 

also, i did change the secondary spring, because they were barely opening. it had the black spring in and i replaced it with the standard spring (no color) i think that was 2 size change. wont the secondary open more with a load on the engine??

 

the standard spring starts to open @2240rpm fully open @8160rpm try using a lighter spring to see if it gets better. i use a short yellow to open the quickest. also check the diaphragm to see if it was pinched or torn during install

 

If it's new carburetor than you should be looking at other stuff. Normally those are OK straight from the box.
I am not sure if this is what carbed C4 is sugesting, but I would use the HLY-12-803 regulator. If it works the same way as HLY-12-704 (that's the one I am using) than you will have one line going in and two lines going to carburetor (you can use one line for each side of the carburetor), but no return line on those regulators.
You need to find the problem and work out all the fuel pressure related bugs before you can go to the carburetor and mess with it (done it my self). Most people makes that mistake and they pay for it. Try to install fuel pressure gauge after the regulator and keep the pressure about 6psi also make sure that it does not changes and jumps all over the place. I was working on my fuel problem for past 4 months and just found out that my brand new pump was bad :U
I spend many hours trying to figure out what's the problem with my carburetor (was I wrong!!!!!!). Since I changed the pump my pressure is nice and steady.
One more sugestion, try to run your fuel from the pump to the carburetor with the return line vs. supply line. I am not sure but that's what I did and it seams to smuth out the pressure, it might be just me but I would try to do it anyway.

When you had the flodding problem, did any gas got into the intake/engine??? If did, you might have a problem with "thin: oil and bad rings. You should get the oil changed and check for cylinder pressure. Fuel will mix with oil and create very thin oil which is very bad for lubricating your motor.


I hope this helps.
Ziggy

 

One more thing that I forgot, do you have vented gas cap????????

:)

 

im using the stock cap. would that be a problem?

 

You defenatly HAVE TO change it. You not getting any air into the tank and your cap is desined to keep the tank pressuraized for the high pressure fuel injected pump. Change the cap or get some air nto the tank some other way.
This will help with fuel pressure, especially when your gas tank is full.
Ziggy

 

thanks for the info--i changed it!!