bEtUr4dRustang

I need some help from the carb gurus who really know their way around the various carbs.

Engine is a zz1 crate motor that was running a 750 cfm holley double pumper and ran really well.

Holley had 72 jets in front and 82 in back with a 6.5 powervalve in the front and a plug in the back.

The holley had no choke provisions, got terrible gas mileage, and I just plain became overly fed up with it one day and so I bought a nice Edelbrock. I know it isn't as performance oriented but this is OK. Its a 1411, thats a 750 cfm edelbrock with electric choke.

As it stands, the car went from running 12.8s to 15.2s with the untuned edelbrock. I just put it on and went to test-and-tune. I made a couple runs, and bumped up the rod size 2 stages and it was slower and ran so rich that it hurt my eyes. So, as I sit the carb is way too rich. I bought the 1489 calibration kit for the 1411 carb I have but it is really only setup to make the carb richer. It seems to cruise at an ok mixture...looking at the calibration charts would tell me to do something that I don't have the rods or jets for.

I have an O2 sensor hooked up.
Idle: .56 V
Cruise: .7-.8
as soon as I get on the car at all, the O2 sensor goes nuts and reads negative, I assume this is because it is so rich and the sensor can only make one volt.

Can you please help me out? I have never had an engine radical enough to require any tuning with an out of the box edelbrock and I have put them on 2 engines in the past. The Holley got me angry too many times and I just didn't want to deal with it.

I bought a 750 because the holley was a 750 and it ran pretty darn well. Engine currently is capable of 345 hp at the flywheel but i will be changing heads and intake around within a month.

I hope i gave enough info.

Thanks guys,
Jay

EDIT: the carburetor still remains a fairly large mystery to me although I can speak for hours about nearly everything else. Hopefully by the end of this i will have a fast car again and know my way around a carb.

bEtUr4dRustang

anybody?

305sbc

iTrader: (3)

Look at your sparkplugs to see if they are black & sooty.

Sounds like you may have one of two problems.

Could be fuel leaking past the needle/seats because of an obstruction or too much pressure.

Also check to make sure both primary & secondary throttle blades open fully when you floor the gas.

Next check the height of your airfilter lid above the mouth of the carb. You need at least 3" of space between the carb and the airfilter lid.

bEtUr4dRustang

Thanks for a reply but eh...well there is nothing wrong with the carb and you missed what I need help with. Nothing is broken, I just need to know about where to go with my calibrations. I emailed Edelbrock and am waiting on a response as to what they think I should order from them to tune it in.

F-BIRD'88

The edelbrock carb you have should run near perfect on your ZZ4, with the out of the box jetting. Something is seriously out of wack. Put the holley back on. See if it runs ok then. You can improve, the fuel mileage by leaning down the primary jetting. to say 68-70.

You may have a bum carb.

305sbc

iTrader: (3)

You say you lost over 2 seconds E.T. but there's nothing wrong.

okay then fine, leave it alone.
You definately don't have a jetting problem.

bEtUr4dRustang

the carb is brand new and I expect I simply do not have it tuned correctly for the engine. Were you being sarcastic when you said I don't have a jetting ploblem? You think its not just something wrong with the jets? I am sorry if I came over as not wanting your help, but from where I stand now, thinking its just a problem with the jetting, it was not useful. However, if its this much slower, its not the jetting?

305sbc

iTrader: (3)

Okay fair enough.
You definately do not have a jetting problem that's costing you over 2 seconds E.T.
There is something else wrong.
The carb is not functioning properly.
This could be due to parts sticking,
small passages getting clogged,
the carb assembled wrong,
or something to that nature. You'd have to get the carb to work right before you even think about starting the tuning/jetting process for power.

Do not rule out ignition problems. Most suspected carb problems end up being ignition related... as in bad plugs or wires. A missfiring ignition will cause O2's to show rich.

I just felt you should actually find the problem before trying to swap jets around.
Again, the jets being a little off will NOT cause you to lose 2 seconds. There is something else wrong there.