Carb Help

i have a 305 with a weiand intake, hooker headers, msd streetfire distributor, and a 650-750 holley carb....my car cranks fine but wont stay runnin if i take my foot off the gas...it runs fine when i rev up the engine..and when i take my foot off the gas its idles down and spit fire out of the carb....i thought i was gettin a good deal on the whole car...i still think i am....the guy sold it to me cuz he thought it was a tapping lifter that he heard while the car was running...come to find out it was a loose rocker arm....i havent checked the timing cuz i dont have a timing light....i also chancged the plugs and they nwere soaked with gas...too much gas maybe?ne help would b appreciated

Sounds like a timing issue to me. Have a friend keep it revved up while you turn the distributor to see if you can get it to run better. You can 'get by' without a timing light, temporarily, by finding out where it starts knocking and then backing it off a couple degrees (barely turning the cap). Turning the distributor clockwise retards the timing and counterclockwise advances.

thanks alot silicon...im going to try that early in the morning...thanks for the quick reply...ill let u know how it goes.

i left out one thing.....i was turning the idle mixture screws on both side of the carb and when i did.....no change in how it was running

you could have a good look at the vac lines ,make sure that there on and not cracked/leaking. it maybe a timing issue along with a holley carb problem.

one more thing pull the dipstick and smell it. if you have a raw gas smell it will more than likely be that the floats are set to high or leaking on the seats causeing fuel to dump in uncontrolled into the engine causing the back fire & wet plugs and the worst gas in the oil. ( fix the carb & change the oil and filter) thats from the "been there done" that file.

ok cool...fixiing the carb...wut exactly do i need to do to acheive this...

650-750 holley carb rebuild book for starters. this is best left to a builder/ good mechanic thats got some holley experience. the holley carbs are for the most part straight forward. here is a link:http://www.chevyhiperformance.com/howto/45798/index.html http://www.chevyhiperformance.com/howto/45798/index.html

wow guys......i jus may b gettin too much gas....i toook the spark plugs out and they were soaked with gas....i mean soaked.....also....i took off the valve covers.....my oil was milky lookin....but not totally white....i have a pic i took but i have to find my usb cable so i can post the pics off the inside valve cover...

i jus found out that the carb is a 600 cfm holley....i didnt think a 600 cfm carb will give a 305 too much gas...is this possible?

this is possible. the carb is like a tank on a toilet. when the gas is pumped into the carb via the pump the float in the bowl will rise with the gas and when it is at the set hight/point the needle-and-seat assembly will stop the gas. if this float is set to high the extra gas floods over the top and floods the engine/washes the cyd walls passed the rings and into the oil pan. the gas will not stop if the needle-and-seat assembly is damaged.

and the needle and seat is wut shoots da gas down into the carb right?

do you think you can set the floats with some direction?

of course....im a fast learner....wut about the milky lookin oil....is dat from the gas too?

ok, :
Air cleaner off.
On the sides of the flost boals, there is a screw head that is about half to /3/4" of the way up the boal. This screw is 1/4" long and has a gasket/O-seal on it. It is easy to drop it is so short.
......these need to be removed.
On the top of the carb there is another screw and it has a nut under it. the location is on the top front float boal and the rear is on the top rear of the boal.
the ones on the sides are for the (eye) sight level.
the ones on top set the floats.
You need a good flat screwdriver and a 5/8" box end wrench.
Put a rag under where the eye holes are. this will catch any spilt gas.
Adjusting the floats is easy.
Loosen the screw head on top 1/8 of a turn, not much more or gas will spit out when running and making adjustments.
You need to hold that screw still and turn the nut. Counter clockwise will lower the float and visa versa.
You should set the floats so the gas just sits at the bottom of the (eye) holes. Some like it to trickel out but if you see the gas is right at the bottom of that hole, Just sitting there, your fine.
If this is a doubble pumper, the front boal will use gas as it idels so setting it is easyer.
On the rear you might need to manually pump the plunger to lower the level in the boal or you might go to low.

If this is parcially your issue and the high low adjustments are out.
dont start the car, pull a coil wire and roll it over so the gas will pump into the boal. this way you can set it easyer without fighting to keep it running.
With screw in boal, roll over engine, remove screw. If gas comes out, lower float. Now do the back one.
I hope this helps. I have to run right now but will be back in two and 2.

thanks alot...ill let u guys know how it goes

Most effective tool for a Holley:

http://mysite.verizon.net/strey/files/HolleyToolKit.jpg

If that's not an option, determine which model Holley you have. The numbers are on the left front of the air horn. I had a Holley on a Performer once. It was a little too much carb for the 283:

http://72.19.213.157/files/1685-Performer.jpg

GAS, good tutorial on the float adjustment! A lot of people dis the Holley carb line, but I like them. I have a set of carbs here that I move from car to car.

I also suggest getting a good basic Holley book, any decent book store will have them or try Amazon.

Bob

http://i255.photobucket.com/albums/hh121/chevy901/003.jpgthis is the carb i have.its an 65-1850s.where the screw u mentioned? http://i255.photobucket.com/albums/hh121/chevy901/001.jpgthis is my valve cover...the milky lookin stuff i dont like to see..gas n oil?

that milky stuff is anti freeze misting up off of the head bolts. if the engine has been worked on some of the old school thinking was to use silicon (rvt) sealer on the head bolts. you can fix this buy removing one head bolt at a time ,clean the head bolt and put pipe sealant ( i used a locktite pipe sealent ) and re torque to the engine specks, Head bolts (sealer on threads).65 ft.-lbs. this will fix this, and a oil & filter change asap after the repair as coolant and bearings do not mix to well. chances are both heads will have to have the new sealant put on and re torque.

looks like that carb is a non external ajustable carb re float ajustment.

thanks for the reply....i talked to a technician from holley and he explained to me that i jus need to take the float bowl off and make sure when the float sits back down that it is parallel to the float bowl...im gonna try lookin at this now to see how it looks....about the head and the head bolts?....the heads need to come completely off with new gaskets put on?....

now im gettin pissed....float level is fine...dont know where else to start

head bolts do them one at a time,put the sealant on the clean threads , install and torque. them easy fix. "been there done" that file

QUESTION Why is my engine running rich and my mixture screws do not have effect?
ANSWER The first thing you need to ckeck is your float level. No fuel should run from the sight hole unless you shake the vehicle. Next check the engine vacuum at idle. (in gear if A/T) if it is 12" or more a 6.5" powervalve will usually be fine. Anything below 12" divide in half. For example 9" vacuum will use a 4.5" power valve. Another possible cause associated with performance cam shafts are exposed transfer slots. You should not see more than .025"-.030" of the transfer slot exposed past the throttle plate at idle.



this was my intial problem i thought i had...running too rich!!!thats y i came to u guys...now that i have checked the float level and it was fine...where do i go...i have no idea of wut he's talkin about when he refers to the vacuum and power valve...can anyone explain them in lamens term please?i got that question from the holley website under the "frequently asked questions page".

Holley carb power valve http://www.chevyhiperformance.com/howto/45798/photo_05.html here is the link to the carb help. http://www.chevyhiperformance.com/howto/45798/index.html

Good call. One moderate backfire, and the original PV is toast. There is a check ball kit to resolve that. If you go shopping for a new PV, make sure you look at the inches vacuum rating stamped in it, and try to get one with rectangular slots rather than holes for the fuel passages.

You can also run a small music wire through the air bleeds (accessible through the air horn) to make sure they are clear.

Yes, the primary bowl looks to be internal adjustment only, but the rear looks like it might have the screw.

You can find some decent information on Holley carbs online if you look for it. www.mortec.com also has some helpful hints.

If the links don't get you what you need, I have a scanned copy of a Holly 4150-4160 manual I can email, but it's about 4 MB, so make sure your email can take it. All I'd need is a good email addy in the PM.

thanks for the help guys...the first thing i planning on doin is gettin that old milky lookin oil out of my engine and everywhere else it might be...then i will go to the junkyard and find me a good lookin quadrajet and put it on to see how it does...i still actually think im gettin too much gas...but...my mind is starting to go blank bout this one...r there any other possibilities....?

so even if my carb has the blowback protection it will still malfuction when a blowback happens?

Everyone Knows The Problem Im Having And I Tank Everyone For Takin The Time Out To Help...i Noticed Something When I Was Under My Hood.....after Putting My Intake On B4 My Problem Started I Noticed That Alot Of My Intake Bolts R Loose!will This Cause The Problem Im Having As Well....could Antifreeze Leak Under The Intake And Go Into The Oil?and Wut About Gettin In The Runners Of The Intake...will That Cause The Car To Run Good On Moderate Acceleration And Eventually Die After Runnin Idle....so My Question....from The Loose Intake Bolts...can Antifreeze Get Into The Gas As It Goes Into The Piston Chamber And Can It Get Into The Oil That Way?

a loose intake = low vac and poor running,oil loss and antifreeze loss. you may get some antifreze into the engine. head bolts are "LEAKING" do them one at a time,put the sealant on the clean threads , install and torque them. easy fix for this problem. "been there done" that file quote"that milky stuff is anti freeze misting up off of the head bolts. if the engine has been worked on some of the old school thinking was to use silicon (rvt) sealer on the head bolts. you can fix this buy removing one head bolt at a time ,clean the head bolt and put pipe sealant ( i used a locktite pipe sealent ) and re torque to the engine specks, Head bolts (sealer on threads).65 ft.-lbs. this will fix this, and a oil & filter change asap after the repair as coolant and bearings do not mix to well. chances are both heads will have to have the new sealant put on and re torque."

http://i255.photobucket.com/albums/hh121/chevy901/001.jpg

the coolant in the engine will presure up to apx 16 lbs and without the correct sealant your head bolts that thread into the coolant part (called the water jacket) will mist the antifreeze up the head bolts and fog/mist the inside the valve cover as your photo shows. it becomes a frigen headache to trouble shoot a auto problem when you do not know what the last person screwed up. i have had to start at the front licence plate and go right though the car to the rear plate to make it a good car. 463

Ok Thanks..do The Intake Bolts Need To Have Sealant On Them Too......wut Color Sealant Should I Use?

use LOCTITE 565 Thread Sealant. this is a single component, high viscosity, low strength acrylic thread sealing adhesive; it cures when confined in the absence of air between close fitting metal parts and resists shock and vibration. Use it for the Head bolts and intake bolts. work smarter not harder.