F-Body Lover

Exactly I will open the secondarys more later and see how it goes,the idle mixture on the secondarys response's very good but on the primary it wont effect that much I will take the screws out and compare them to another one maybe they are shorter or something

F-Body Lover

ZONES what do you think about drilling a hole in the plates?

F-Body Lover

ZONES can you use secondarys metering block on primary's? I've found out that the problem is from the metering block on the primarys it back fires and hesitate if I put the new one but if I put the old one it works but the idle is 1500rpm and the mixture screws wont effect anything can I use the secondarys one on primarys? the primary metering block has timing advance port so I dont know

ZONES89RS

iTrader: (25)

As long as the secondary is adjustable and has a provision for a power valve.

F-Body Lover

can spark plug wires lead to backfires and hard start? because I toke a timing light from a friend of mine and #1 cylinder wasnt shooting light constint it was like shooting for 3 times and off for a while then shoot more and off he told me that there is something wrong with the timing light but I checked on other wires they were shooting light but off for less time than the #1 cylinder I will get new wires tomorrow and see what happens I dont think its from wires because they are 3 months old ! I hope its from the wires

AutoRoc

2 things to check. First.. Take the distributor cap off and clean all of the contact points off on the inside. Use some fine sand paper or similar abbrasive. 2nd..Make sure all the wires are on the correct cylinders. and YES... if the wires are a few years old and touching each other, or even touching the coil and it's wires, it causes backfires and HORRIBLE running conditions. I just ran into this issue myself. Keep the wires away from each other. I installed a new box before figuring out that the wires were arcing each other... hahaha

Goodluck with the new cam if you bought it yet. I'd reccomend filling out Bullet Cam's spec sheet. They give you a price and the cam specs, and lobe numbers. They run like $325 and are a billet steel core. Used by LOT of the best heads up racers and they know what works in a street car also. My cam guy consulted with Bullet and had them make mine. 259/263 @ .050" .664" lift on a 112 lobe sep. Spins to 7700rpm so far, idles at 1250rpm with a nasty crackle..

F-Body Lover

Autoroc big thanks to you man I just bought new wires I will hook them later and start the car and I hope everything works fine

F-Body Lover

I really hate my car I changed the wires and used my carb and still no use yesterday we found out there are two wires dont signal right and when we changed one wire only the idle was so smooth and it was 1K rpm I really dont know what to do

pancherj

Some things to try -

Pull all of your plugs and put in new ones. Pull the cap and make sure there are no issues there (MSD boxes and high voltage coils are hard on caps). Check the connections at the distributor...just in case. Start the car and get it to idle at as low of an RPM as possible (even if it is 2000RPM). Shut off the car. Check all of the header pipes to see if some are noticeably cooler (use your finger or a thermocouple from a Fluke tester). Then, pull all of the new plugs out and see what they look like.

This may help isolate which cylinders are giving you the problem. If you have an MSD box, I think there are some tests you can run on that to make sure it is operating correctly.

speedy55

drilling holes in the throttle blades allows air to pass through with out the Idle transfer slot being exposed. i have them in mine and it helped tremendously.

speedy55

checking to see which cylinders need attention is easy. Use a spray bottle and shoot the header tubes after you turn it off. the ones that dont sizzle and dry up immediately aren't burning all the gas. i used to run a tunnel ram on the street and I know this works!

F-Body Lover

Im not running any box's its just Mallory 85 distributor with NGK TR7 recommended by a racer in my country are they too cold for my set up? I will change the intake manifold later and ee what happens

F-Body Lover

what was your set up and which carb? how big the hole you drilled? can I have the size in mm because our shop's here they deal with millimeter not in inch's

speedy55

mine are 3/32 but I started smaller and gradually increased.

VERY IMPORTANT! iF THE IDLE MIXTURE SCREWS ARE HAVING ANY EFFECT ON THE IDLE QUALITY OF THE CAR THIS MAY NOT BE THE MODIFICATION YOU NEED!


looking down the carb with a flashlight look at the front side of the throttle bore for the idle transfer slot ( it is very small) if it is exposed with the idle speed screw set in the idle position this will more than likely help cure the problem.

F-Body Lover

only secondary mixture screws does effect the primary's are not I will drill it anyway

speedy55

drill both sides (primary and secondary) on the side of the blade closest to the center of the carb and start small. then close the blades all the way and try to start the car and adjust the idle speed screws til you can keep it running and then start on mixture. Once you get themixture screws as close as possible you can then go back and readjust sidle speed.

F-Body Lover

is there any chance you have a picture that shows the holes?

F-Body Lover

I drilled the holes and I drilled the air bleeds too they were too small that sometimes I think its 450cfm carb not 750 !! will bolt it tomorrow and see what happens

speedy55

I have never drilled AIR BLEEDS as it is too easy to screw up.
A 450 carb does not have a secondary metering block if I remember correctly.
Is there a number on the choke housing area? this will tell you what the carb started life as.

F-Body Lover

they cannot be changed thats why I drilled them and noo I didnt mean its 450 carb I meant that the air bleeds were too small that you think its 450 not 750 carb